Collection of Master's theses

Faculty of Civil Engineering and Geosciences

Civil Engineering and Geosciences Stevinweg 1 PO Box 5048 2600 GA Delft The Netherlands T +31(0) 15 27 85440 F +31(0) 15 27 87966

Collection of Master’s theses Collection of Master’s Theses March 2012

March 2012

2 | Master’s Theses March 2012

Master’s Theses Civil Engineering and Geosciences March 2012

Civil Engineering and Geosciences Stevinweg 1 PO Box 5048 NL 2600 GA Delft The Netherlands Telephone: E-mail:

+31 (0)15 2784023 [email protected]

2 | Master’s Theses March 2012

Table of Contents Preface 7 What is the graduation book exactly? 9

Civil Engineering theses

11

Building Engineering

11

Connecting Modular Floating Structures Student: M.J. Koekoek

12

Adaptibility of structures Student: A.J. van Westenbrugge

13

Reinforcement Toolbox Student: J. Lauppe

14

Timber stadium Engineering Student: T. van den Boogaard

15

Medium rise timber buildings in the Netherlands Student: S. van Egmond

16

Structural feasibility of a demountable football stadium Student: M. Loosjes

17

Prestaties van thermisch comfort installaties in NL Student: P.C.M. Zegers

18

Structural Engineering

19

Vortex-induced vibrations of suspended floating pipelines Student: N.E. Oikou

20

Torsion in ZIP bridge system Student: E. van Vliet

21

Feasibility of using activated paper sludge recycled minerals Student: M. Ahammout

22

Progressive collapse in design of bridges Student: S. van Wijk

23

Interaction between plate and column buckling Student: A. van Ham

24

Most cost effective connection between arches Blalobridge Student: H.R. van der Land

25

Feasibility of Tall Timber Buildings Student: S.G.C. Timmer

26

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Hydraulic Engineering

27

Primary dikes in Limburg Student: L.M. Groendijk

28

Flooding and sediment management on the Koshi alluvial fan Student: E.M. Hooning

29

Erosion in the tide-influenced Rhine-Meuse delta Student: T. Smits

30

The Lagos coast Student: K.M. van Bentum

31

Impact of re-surfacing groins on hydrodynamics and sediment transport Student: A. Hendriks

32

Probabistic Modelling of Extreme Beach erosion using XBeach. Student: M. Riesenkamp

33

Edge scour around an offshore wind turbine Student: E. Simoons

34

Process-based modelling of morphological response to submerged breakwaters Student: R.J. Vlijm

35

Dune erosion near sea walls Student: B.B. de Vries

36

Flexible scour protection around cylindrical piles Student: G. van Velzen

37

Pre-Posterior Bayesian Analysis Student: S. Al-Baz

38

Baggerpluimen – Ecologische risicoanalyse Student: J.H. Becker

39

The floating construction method Student: R. Hendriksen

40

The feasibility of a commercial osmotic power plant Student: R. Kleiterp

41

Differences between a 3 dimensional probabilistic and the traditional method of berthing structure design Student: J. Kool

42

Risk to life due to Flooding in post-Katrina New Orleans Student: A.L. Miller

43

Rip Current Characteristics at the Dutch Coast Student: G. Winter

44

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Port of Rotterdam Anchorages Study Student: S.B. Devillé

45

Sedimentation in the Botlek Harbour Student: A. El Hamdi

46

Coal transport Kalimantan Student: B.C. Joppe

47

Analyzing the hydraulic design for the new basin in the IJmuiden outer harbor Student: P. Kaufmann

48

Pump jets in inland vessels Student: J.R.C. Manaois

49

Optimizing the passage of fast ferry navigation at the Schellingwoude lock complex Student: M.J. Rispens

50

Flexible Port Infrastructure on Maasvlakte 2 Student: R. Ros

51

Development Plan Dordrecht Seaports Student: M.J. Verhage

52

Geo-Engineering 53 Time dependent processes on passive loaded piles Student: K. Siderius

54

Modelling and Effects of Rapid Impact Compaction Student: J. Vink

55

Watermanagement

57

Analytical Modeling of Salt Intrusion in the Kapuas Estuary Student: F. Gevers Deynoot

58

Moisture Recycling and the effect of land-use change Student: R. Nikoli

59

Memstill for wastewater: Effects of surfactants in the feed solution Student: N.T.T. Hung

60

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Biofouling and organic micropollutants rejection Student: N.T. Quach

61

Operationalization of SoilDTS Student: J.H.A.M. Jansen

62

The world’s freshwater resources are threatened Student: M. Hegnauer

63

Transport & Planning Study of evacuation behaviour during a flood Student: S.L. Hek

Last year’s Theses

65 66

67

Master’s Theses October 2011

68

Master’s Theses June 2011

70

Master’s Theses February 2011

72

Master’s Theses October 2010

74

Research groups and professors within the faculty of Civil Engineering and Geosciences

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76

Preface

Every four months we publish a collection of abstracts of the theses produced by our recent Master’s graduates. In this collection you will find the theses of students who graduated in March 2012. We train our students to be more than just communicators of theoretical knowledge. We also teach them to be critical, make thorough problem analyses and take account of social contexts. We are convinced that a combination of theoretical knowledge and practical skills is needed to find effective solutions for social problems. The graduation project and associated thesis form the culmination of our students’ degree programme. In their graduation projects they examine a concrete problem and are required to employ all the knowledge they have gained during the previous years. By successfully completing this last step they have proven that they deserve to carry the title of Master of Science and that they are ready for the challenges of professional practice. In an age when the role and qualities of engineers are subject to more and more critical scrutiny, our graduates are still being welcomed with open arms by the labour market. They disperse to find jobs in various industries and most of them are offered work almost straight after their graduation. I see this as proof that a demand exists for the knowledge and skills of our graduates. So it is with pride that I present you with this collection of thesis abstracts. They demonstrate the high level that our graduates have attained and the breadth of the subject matter they have mastered. I would like to thank all those colleagues who contributed to this work with such energy and commitment. I wish our graduates every success with their careers and I trust that they will be just as enterprising in their future roles as they were during their studies. I hope that they continue to learn and create and keep testing the boundaries of the civil engineering industry. Professor B.M. Geerken Dean of the Faculty of Civil Engineering and Geosciences

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What is the graduation book exactly? “Master’s Theses March” contains summaries of the theses produced by various students who obtained a Master of Science degree at the Delft University of Technology. The students in question graduated in “Civil Engineering”. The purpose of this publication is to inform professionals working in these fields about recent developments in teaching and research at the Faculty of Civil Engineering and Geosciences. In many cases, the subject of the Master’s thesis is based on a request from professionals working in the field in question. In other cases, such individuals will collaborate in the realisation of a Master’s thesis. Alternatively, the thesis may be part of a wider research project within the department itself. The primary goal of the Master’s thesis is to round-off a student’s course of study at the TU, and to enable them to graduate as a Master of Science. As the regulations stand, this requires an investment of 22 to 26 weeks of study. The summary of every completed thesis is published in “Master’s Theses March 2012”, whether they are merely average or truly outstanding.

The book’s layout The summaries of the various theses are published per Master’s programme and specialisation: • • The Civil Engineering Master’s programme has six specialisations: • • Structural Engineering • • Building Engineering • • Hydraulic Engineering • • Geo Engineering • • Water Management • • Transport & Planning

The aim of the book The main purpose of publishing these Master’s theses is to ensure that the outside world is better informed about the research that is carried out at the Faculty of Civil Engineering and Geosciences. It is also hoped that this book will enhance communication with professionals working in this field, and help them to become better informed about the capacities of current graduates.

Further details Contact the department in question if you require further details about one or more of the published summaries (the phone number is given at the end of each summary). A small charge is sometimes levied to cover the costs of printing and posting a thesis. It is not always possible for us to send complete theses. If you so wish, you can also make an appointment to view a particular thesis. Department of Education & Student Affairs 015-27 81199 / 81765 Department of Marketing & Communication 015-27 84023

Further information: Delft University of Technology Faculty of CEG, Department of Communications PO Box 5048 2600 GA Delft The Netherlands

All of the summaries have a similar layout. Email the department in question if you require further details about a specific thesis (the email address is given at the end of each summary). The section containing the new summaries is followed by a comprehensive list of those produced last year. The layout of these summaries reflects that of the previous publications. A Master’s programme spans several different departments, each of which corresponds to a specialisation within the programme in question. At the end of this book is a comprehensive list of specialisations, which includes the names of their respective professors.

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1. Civil Engineering theses

Building Engineering

1

Building Engineering

Connecting Modular Floating Structures A General Survey and Structural Design of a Modular Pavilion

Introduction The changing climate results in increasing water problematics for the Netherlands; too much water at one moment and water shortage at another. An answer to these water problematics is water storage, which could be realised with more surface water. However, more space for water conflicts with other area-claims. Building on water is an answer to this conflict of interests. This one of the reasons why building on water has taken a flight in the Netherlands. The expectation is that building on water will increase further, as there are already plans for living quarters existing of floating structures. However, the experience with building on water is still limited and new floating projects counter multiple problems. Connections in between floating structures are for the Dutch construction industry still a rather unmapped territory. In this thesis a general survey is done on building on water with all relevant issues. Connections have been researched more elaborately. With a case study of a floating pavilion this knowledge has been applied.

Case study floating pavilion

largest self weight by far, so these are the main determining factors of the draught of 0,88m. The normative waves resulted in internal forces which are in the same range as the internal forces by imposed loads. It is not necessary to decrease the internal forces by movement allowing connections, thus the connections between the beams can be executed as rigid connections.

Designed connection The designed connection between the floating bodies consists of the following: Trapezoidal ridges, for self alignment and shear forces A vertical steel pen with a wedge shaped point, for the tension connection at the bottom side. This pen will be easily to insert and to fix from the top of the floating bodies. A longitudinal bolt as tension connector on the top side and for pre-stressing the connection. Elastic material in between, for amongst others preventing small relative movement (which will exist by allowing deviations) and for impact damping.

The floating pavilion, with dimensions of 24x46 metres, has already been constructed, but it has been constructed in one piece. In this thesis a structural design has been made for a modular pavilion, in a way the separate spheres should be switchable and removable. A combination of EPS and a concrete framework has been found the best floating system for the pavilion, since this results in an unsinkable and light floating body with a low draught. It appears that the concrete beams and floor of the floating body result in the

This design has resulted in a connection easy in execution, since it provides self alignment and only actions from the top are needed. The connection does allow tolerances but will still provide a very rigid connection, since it can be tightened.

Student: M.J. Koekoek Thesis Committee: Prof.dipl.ing. J.N.J.A. Vambersky, Ir. W.J.M. Peperkamp, Ir. K.C. Terwel, Ir. W.F. Molenaar, Ir. B. Hofmans-Karatay For further information, please contact the section of Building Engineering tel. 015 - 27 83990 Email: [email protected]

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1

Building Engineering

Adaptibility of structures Optimization of the use of materials in new, adaptable and sustainable structures Due to growing environmental problems on our earth, the relevance

Within the context of the case study the use of an (steel or timber)

of an optimized use of materials within the building industry becomes

adaptable bearing structure results in a lower environmental impact

increasingly relevant. However, building structures are often not

per square meter compared to the concrete flexible and steel, timber

designed for changes to allow such material optimizations or other

and concrete traditional building structures. Between the adapt-

desired structural changes. In flexible structures the use of materials

able bearing structures the timber (laminated redwood) adaptable

is not optimized due to the over-dimensioned structure, resulting in a

structure performs best environmentally. It should be pointed out

surplus of material in the structure.

that when using timber in the adaptable structure, sustainably grown

Adaptable bearing structures could overcome the limits of the tradi-

timber should be used. If standard grown timber would be applied the

tional structures and surplus of materials of flexible structures, in that

steel adaptable structure environmentally performs better than the

adaptable structures could be changed to the likings of the user and

timber adaptable structure (see figures 1 to 3).

in addition allow the optimization of the amount of used material to comply with the desired structural changes. Inspired by the concept

Overall, it can be concluded that within the context of the case study

of ‘Trias Materia’ and the Cradle to Cradle philosophy, a research is

an adaptable structure would be more sustainable to apply, regarding

done to ‘adaptability of building structures’.

the use of material, compared to a flexible or traditional structure. The amount of material can be optimized in an adaptable structure

Within this MSc thesis different building-structure models are gath-

and in addition the adaptable structure is the only type of structure

ered and the variable quantities in and around building structures

to ‘evolve’ into different building volumes without a surplus of used

are analysed, subsequently the most relevant changes in society that

materials. The elements and components used in an adaptable struc-

impact buildings and building structures are examined. Currently

ture are available for reuse elsewhere when becoming obsolete in a

frequently occurring desired changes to buildings include an altera-

structure.

tion of the building volume or a change of function within a building volume. Although currently lots of office buildings experience the limits of static building structures, the solution sought within this thesis is only relevant for the future since a new adaptable structure is designed. In the future educational buildings could very well suffer the same fate as the current office buildings. A solution might be to design

Figure 1: The environmental costs per m 2 for different types of struc-

the contemporary educational buildings with an open vision towards

tures in case of a scenario without any structural changes.

the future; incorporating lots of scenarios without using a surplus of

Figure 2: The environmental costs per m 2 for different types of struc-

building material, using an adaptable structure.

tures in case of a scenario with a contracting building size.

The educational building of the ‘Haagse Hogeschool Delft’ is used as a case study for the design of adaptable bearing structures that can change in time, following various scenarios while maintaining an optimized use of the amount of material in time. The adaptable structures are designed to be ‘changeable’ in the bearing capacity of structural members within the adaptable structure; optimizing the structure to the circumstance it finds itself in. Subsequently the adaptable

Figure 3: The environmental costs per m 2 for different types of struc-

structures are compared to flexible and traditional structures in the

tures in case of a scenario with an expanding building size.

similar context of the ‘Haagse Hogeschool Delft’, to investigate any differences in the material related environmental impact caused by the application of any of these types of structures.

Student: A.J. van Westenbrugge Thesis Committee: Prof.dr.ir. E.M. Haas, Ir. S. Pasterkamp, Ir. S. Van Dijk, Ir. T.J.J. Huijsmans

For further information, please contact the section of Building Engineering tel. 015 - 27 83990 Email: [email protected]

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1

Building Engineering

Reinforcement Toolbox A Parametric Reinforcement Modelling Tool for Curved Surface Structures Recent years have witnessed the realization of multiple concrete curved surface structures. The often complex geometry of these structures led to new challenges in the final design and production phase: design of the reinforcement is one of these challenges. Current reinforcement modelling software is not capable of properly dealing with NURBS curves and surfaces. The absence of proper reinforcement tools for curved surface structures renders the structural engineer less effective in designing the reinforcement. This can lead to missing out on potential through ill-informed design decisions. The computational strategy proposed in this thesis provides a way of improving the design process of reinforcement in curved surface structures. It includes all necessary steps of raising an architectural curved surface model to production level in terms of reinforcement. Three design aspects have been distinguished: geometrical control, structural analysis, and production. Corresponding to these design aspects, three concepts have been developed: the SolidModel, FEM Analysis visualization and Rebar DNA which help to control them. The developed Reinforcement Toolbox supports the strategy by offering structural engineers a tool which can be used to control the design aspects of reinforcement in curved surface structures. It sets out to help remove the current split between draftsman and structural engineer by offering a design environment which offers the possibility to simultaneously model and verify reinforcement for curved surface structures. Functional requirements which emerged from the computational strategy formed important input for the developed architecture of the Reinforcement Toolbox. Use cases helped to identify different scenarios in which the software application is likely to be used. The system architecture of the Reinforcement Toolbox has been developed with strong attention to the multifac-

eted design process of reinforcement in curved surface structures. It builds on existing 3D modelling software, Rhinoceros and Grasshopper, by adding custom components. The Reinforcement Toolbox has been developed using Microsoft Visual Studio 2008 and written in C#. In accordance to the possibilities offered by this object oriented programming language, the Reinforcement Toolbox uses a collection of custom objects which can be considered the building blocks of the Toolbox. For the first version of the Reinforcement Toolbox several components have been developed. Together they offer the necessary functionality for a structural engineer or CAD draftsman to design longitudinal reinforcement groups and reinforcement meshes for curved surface structures. A first version of the Reinforcement Toolbox has been developed and tested. It can be applied to both complex curved surface structures as well as non-complex structures, making it a widely applicable design tool. Users can apply the Reinforcement Toolbox at their own discretion within any given stage of the reinforcement process either to quickly research different reinforcement design alternatives, or use it to build extensive reinforcement models. The parametric reinforcement models are easily adaptable to design changes, which makes them valuable throughout the entire reinforcement process. The Toolbox has been designed considering user friendliness, and freedom of use. The modular setup allows users to combine components at their own discretion allowing for the intended freedom when designing reinforcement. It has been demonstrated to a group of structural engineers, who recognize the potential it can bring to the reinforcement process, especially when its current functionality and scope will be expanded.

Student: J. Lauppe Thesis Committee: Prof.dr.ir. J.G. Rots, Dr.ir. J.L. Coenders, Ir. H.R. Schipper, Ir. A. Borgart

For further information, please contact the section of Building Engineering tel. 015 - 27 83990 Email: [email protected]

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Building Engineering

Timber stadium Engineering A feasibility study

In recent years, various types of plate-like timber materials have been introduced to the building industry, offering a wide range of new possibilities. Due to a lack of knowledge on these possibilities, in the Netherlands, the material is not used as often as could be expected. In this thesis, it is investigated whether it is feasible to engineer a stadium structure that is composed of timber elements to the utmost extent. The focus is on the structural system, the floors and the grandstands. As a reference, use is made of the architectural design of the Euroborg stadium, which was designed and engineered by BAM Advies & Engineering in recent years. The first part of the thesis provides an introduction to the most important aspects concerning the design and engineering of a stadium structure. In addition, reference projects are discussed to provide insight in the possibilities of timber as a structural material. Thereafter, there is elaborated on the preliminary design. Investigating several structural systems it is found that a timber core system proves to be most beneficial. Decisive factors are the excellent fitting to the architectural design and the ease of erection. The proposed cores have a height of 19.22 m and are compiled from 4 walls, having a width of 5 m each, which are made from LVL elements. Analysing various floor products that are available on the market, timber hollow core elements called Lignatur appeared to be most beneficial to be implemented in the design. These span 14.4 m between the front and the back façades of the stadium structure and are supported by glued laminated timber support beams.

Evaluating the preliminary design phase, an expert on construction technology posed questions on the erection of timber cores with the proposed dimensions. It has therefore been investigated what structural consequences it holds when the core is divided in storeyhigh segments. It appeared that several measures are required to transfer the acting stresses at the horizontal joints. A feasible solution is acquired by applying a combined system consisting of glued-in rods and shear plates. Subsequently research has been performed on the distinct connections that are present at the LVL core. Due to the limited dimensions of the LVL elements (max 2.5 m), a large number of fasteners is required to obtain the required wall width of 5 m. The above is considered undesirable, wherefore it was investigated whether the core walls could be compiled from CLT elements, which are available in widths up to 4.8 m. Accounting for the results obtained, it was concluded that the structural behaviour of these elements is less beneficial than for LVL, but that they do comply with all requirements. As a final check, the core walls have been checked on buckling and their behaviour under fire conditions. It appeared that the proposed core complies with all requirements. With regard to the research question it is concluded that, from a structural point of view, a stadium of which the structure is compiled from timber elements is a feasible solution. The results as presented in this thesis are still preliminary, wherefore several recommendations are made to improve the design.

When the grandstands are concerned, 4-tier elements made from LVL are introduced. Accounting for grandstand elements with an increased riser height the maximum span-width becomes 10.4 m, where vibrations are governing and under the condition that the grandstand support beams are infinitesimally stiff. Accounting for Glulam support beams, the maximum span-width decreases to a certain extent.

Student: T. van den Boogaard Thesis Committee: Prof.dr.ir. J.W.G. van de Kuilen, Ir. G.J.P. Ravenshorst, Ir. P.A. de Vries, Ir. S. Pasterkamp, Ir. V. Van der Wal For further information, please contact the section of Building Engineering tel. 015 - 27 83990 Email: [email protected]

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Building Engineering

Medium rise timber buildings in the Netherlands

Introduction Building with timber is gaining in popularity throughout the world. Increasing environmental awareness and interesting new products from the timber industry provide a basis for new construction designs. Due to the environmental advantages of timber construction, a worldwide interest in medium rise timber buildings is expected. A lot of research is conducted and pilot buildings are made in order to gain more insight in the performances and structural behaviour of medium rise timber buildings.

Problem definition In the Netherlands, timber is rarely used as primary material in medium rise buildings. With only a few erected medium rise timber buildings, the production of these buildings in the Netherlands is still very small compared to the total medium rise production. Because of this, timber as a construction method is an uncommon choice for designers and contractors to make. This results in a little and slow growing experience with timber. Therefore this research examines the technical feasibility of timber as a load bearing structure in medium rise buildings based on Dutch design requirements.

Research The use of timber as the main load bearing structure in Dutch medium rise buildings is examined by designing a 12 storey high hotel (Inntel hotel, Zaandam) using timber as the primary load bearing structure. The design of the structure is based on the massive timber construction, consisting of cross laminated timber (CLT) panels. CLT panels consist of several layers stacked on one another at right angles and glued together in a press over their entire surface area to obtain both wall and floor panels. The material is extremely strong and stiff considering its low density and is also quite easy to process and assemble with ordinary tools making the use of CLT in medium rise buildings very suitable.

Knowledge is also gained by studying three existing medium rise buildings comprising a CLT load bearing structure. The studies show the utmost importance of a good preparation and understanding of the material for acquiring a high performance building.

Conclusion The research proofs the technical feasibility of timber as a load bearing structure in Dutch medium rise buildings. Buildings which are most suitable for a timber load bearing structure are buildings which have little deviations in the structure and where enough space is reserved for shear walls, like apartment buildings. Buildings where large open spaces are required, like office buildings, are less suitable for timber construction because it is more difficult to comply with the stability requirements.

Student: S. van Egmond Thesis Committee: Prof.dr.ir J.W.G. van de Kuilen, Ir. S. Pasterkamp, Ir. G.J.P. Ravenshorst, Ir. P.A. de Vries, Ir. W. van Winden For further information, please contact the section of Building Engineering tel. 015 - 27 83990 Email: [email protected]

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Building Engineering

Structural feasibility of a demountable football stadium

During this master thesis, research is done on the structural feasibility of a demountable football stadium. To avoid derelict stadiums after one-off events such as the World Cup or Olympic Games, a solution is found in the application of a demountable stadium that can be relocated once a year. The goal of the research is to present a preliminary structural design of a demountable and transportable (football) stadium based on the flying shell concept of Zwarts & Jansma Architects. Based on ideal lines of sight and a limited viewing distance to the centre of the field a distinctive stadium results with an undulating upper edge. The applicability of shell action to create an efficient structural system to the stadium is researched with the help of the method of graphic statics. The 2D results of this study are placed in a 3D context to examine the usefulness to the stadium. Based on these results, four configurations are examined with the help of a computer model to check hypotheses and to gain further insight to allow the design of a final model. A final model is chosen on the basis of behaviour under loading, functionality, ease of assembly and appearance. This final model is tested on ultimate limit situations and serviceability limit state situations. Dynamic behaviour happened to be a critical issue that needed further research. Adjustments to the final model are made to improve the dynamic behaviour of the stadium.

In addition to structural behaviour, research is done on the assembly, demountability and transportability of the stadium. Transportation limitations cause the stadium to consist of many small elements that are designed to create maximum uniformity. The order of assembly is based on direct stability, together with shell and ring action providing stiffness during assembly. This is achieved by erecting the stadium layer by layer. The structural system is based on the principle of shell action. Within this principle, double curvature is a very important criterion to ensure structural stiffness. Results of the models that are investigated showed a lack of structural stiffness resulting in a low natural frequency of the total structure. This has major consequences regarding the grandstand structure, as the load spectrum of dynamic crowd loads lies within the response frequency of the grandstand. Either natural frequencies should be increased, or severe measures should be taken regarding the increase of damping capacity, monitoring oscillations in the stadium or design for a dynamic amplification, to rectify this. In order to increase the natural frequency of the stadium the stiffness needs to be increased. The most efficient way to do so with regards to shell action is to increase (double) curvature. Tangential curvature is based on ‘C’ values and preferably should not be altered. Radial curvature is almost absent and needs to be increased. In the situation where natural frequency will not be increased, damping capacity should be increased dramatically by means of the application of dampers at connections or integrated into preassembled elements. The response of the stadium should be monitored and measures taken whenever predefined movements are exceeded. Regarding finance, recurring and non-recurring costs are taken into account. The structural system should be proven to be feasible before financial implications are investigated in more detail.

Student: M. Loosjes Thesis Committee: Prof.ir. R. Nijsse, Ir. K.C. Terwel, Ir. A. Borgart, Ir. J. Arts, R.J. Torsing MSc., Dr.ir. R.D.J.M. Steenbergen For further information, please contact the section of Building Engineering tel. 015 - 27 83990 Email: [email protected]

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Building Engineering

Prestaties van thermisch comfort installaties in NL

Heden ten dage zijn er onoverzichtelijk veel verschillende klimaatinstallaties. Deze installaties geven vaak problemen in verschillende fasen van het bouwproces, zo ook in de ontwerpfase. In dit werk is een selectie van meest voorkomende installaties in de woningbouw integraal onderzocht in haar omgeving om de thermische en energetische prestaties vast te stellen. Om deze installaties te kunnen onderzoeken is er voor gekozen om zelf een computermodel op te zetten op basis van de Eindige Elementen Methode, waarin zowel het bouwfysische als het installatietechnische onderdeel zijn gemodelleerd. Het model is iteratief in overleg met bouwfysische en installatietechnische adviseurs tot stand gekomen. Het model is gevalideerd met behulp van VABI, door handmatige nacalculaties, en door vergelijkingen met andere reeds voor handen zijnde referenties.

Resultaten Uit het computermodel blijkt dat de thermostaat van grote invloed is op het gewenste binnenklimaat. Veel thermostaten meten enkel de luchttemperatuur en regelen de installaties dus niet op basis van de operatieve temperatuur. Hierdoor slaan luchtverwarmingsinstallaties te snel af, terwijl vloer- en wandverwarming te laat afslaat. Bij een regeling op basis van de operatieve temperatuur is de opwarming bij vloerverwarming nog steeds traag ten opzichte van radiatoren, terwijl (lokaal opgewekte) wand- en luchtverwarming 15 tot 30% sneller verwarmt. Dit komt doordat de laatste twee de warmte direct afgeven aan het vertrek, terwijl de ‘zware’ installaties eerst een watervoerend pakket en andere massa moeten verwarmen. ‘Zware’ installaties kennen dan ook nog steeds meer overshoot en energiegebruik als gevolg daarvan. Luchtverwarming gebruikt meer energie, omdat deze een ventilator gebruikt. Elektrische wandverwarming kent vergelijkbare energetische prestaties als radiatoren. Een warmtepomp (WP) verbruikt de minste primaire energie, maar kent zo een laag vermogen dat ze continue aan moet staan voor een goede verwarming. Tevens hebben ventilatie-installaties als warmteterugwinning (WTW) en vraagsturing (VS) invloed op de opwarming en het energieverbruik. VS zorgt ervoor dat er voor dat er bij afwezigheid maar 10% warmte verloren gaat t.o.v. 30% bij WTW en warmt dus sneller op.

WTW kent echter minder energieverbruik, omdat deze ook bij aanwezigheid functioneert en dan ook tot 70% van de warmte terugwint. Onderzoek naar gebruikerspatronen heeft opgeleverd dat het continue laten aanstaan van de verwarming in een goed geïsoleerd gebouw 10 tot 15 % meer energie kost. Het kost slechts 1% wanneer ook WTW wordt toegepast. Tenslotte blijkt voor de zomer van belang dat er warmere zomers bestaan dan waar de normen nu rekening mee houden en die dus regelmatig overschreden worden. Verder blijkt het vermogen van koeling ontzettend van belang, omdat temperatuuroverschrijding vaak met grote warmtelasten gepaard gaat. Men moet tevoren preventief koelen om aan de normen te voldoen. Als het koelvermogen dan ook nog gering is, zoals bij een WP het geval is, is het moment dat de WP aanvangt met koelen vaak al te laat. Daarbij blijkt elektrische koeling bij een hogere setpoint (dus niet preventief) vergelijkbare energetische en thermische prestaties te behalen als een WP-koeling.

Conclusies Een regeling op basis van de operatieve temperatuur kan 10 tot 20% energie besparen bij veel verwarmingsinstallaties. Het verdient aandacht om regelingen door te ontwikkelen en aan te passen. Elektrische installaties blijken een betere thermische prestatie te kunnen leveren voor de opwarming. In combinatie met aanwezigheidsdetectie kan het 10 tot 15% energie besparen te opzicht van andere verwarmingsinstallaties. Het is echter gunstiger om continue te verwarmen met bijv. aardgas of zelfs een WP, in combinatie met WTW, gezien het primaire energieverbruik van elektrische energie. Zo hoeft dan helemaal niet meer opgewarmd te worden en dit kost slechts 1% meer energie. Voor koeling is er nog geen comfortabel alternatief voor handen. Verder verdient het aanbeveling om andere klimaatjaren als referentie te gebruiken. In een eventueel vervolgonderzoek kan luchtkwaliteit worden meegenomen in het computermodel.

Student: P.C.M. Zegers Thesis Committee: Prof.dr.ir. A.A.J.F. van den Dobbelsteen, Ir. A.C. van der Linden, Ir. J.F.E. van der Vliet, ing. S.R. Kurvers, Ir. H.R. Schipper For further information, please contact the section of Building Engineering tel. 015 - 27 83990 Email: [email protected]

18 | Master’s Theses March 2012

2. Civil Engineering theses

Structural Engineering

2

Structural Engineering

Vortex-induced vibrations of suspended floating pipelines

The major changes that took place in the offshore industry during the last decade led to the need for design of suspended floating pipelines. Once installed the pipe may vibrate due to vortices that occur due to flows around it. These vortices induce the pipe vibrations, which are called vortex-induced vibrations (VIV) and may damage the pipeline and limit its fatigue life. These vibrations are considered as one of the most crucial threats for pipelines and their management is critical to the pipe design and operation.

Project objective The thesis is devoted to the development of appropriate models to describe vortex-induced vibrations of suspended floating pipelines. Main objectives of this thesis were:To study the phenomenological modelling of vortex-induced vibrations of an elastically mounted rigid cylinder in fluid

In these lock-in ranges the in-line versus the cross-flow oscillation revealed

flow. To develop an appropriate model that predicts the hydrodynamic

a figure-eight pattern and the cross-flow oscillating frequency has been

behaviour of a free spanning suspended floating pipeline.

found to be equal to the vortex lift force oscillation frequency and equal to half the in-line vibrating frequency, as expected. At the lower band of

Research

reduced velocities the in-line versus the cross-flow oscillation were found

In the first part of the thesis the vibrations of an elastically supported rigid

to be crescent-shaped, while at the unlocked ranges it was not found to

circular cylinder constrained to a stationary and uniform flow were studied.

maintain a certain pattern. The boundary conditions have been found to

Main goal of the modelling was the development of a model able to predict

influence significantly the lock-in range, with the latter being longer in

the measure-ments of free and forced vibration experiments. To this

case of an elastically mounted pipe than in the simply supported cylinder.

end, four different phenomenological models have been employ-ed. The

Above a certain reduced velocity, the improved Ogink-Metrikine model

models were analysed numerically in the time domain and the predicted

predicted large oscillations in the in-line vibration, which has to be verified

amplitudes and frequencies of the cross-flow oscillation were compared to

experimentally.

existing experimental data from free vibration tests. The vortex lift force coefficient has been analysed in two components, one with in phase with

Conclusions and recommendations

the body velocity and one in phase with the body acceleration and contour

The comparison of the predictions of the different phenomenological

plots have been created over a range of amplitudes and reduced velocities.

models showed that the introduction of the fifth order model for the lift

The obtained graphs have then been compared to contour plots of vortex

force did not lead to significant improvement of the results compared to

force coefficients that correspond to forced vibration experiments. In the

the frequently used Van der Pol model. Further research in this direction is

second part the vibrations of a free spanning suspended floating pipeline

recommended and might lead to a simple one-oscillator model that could

were studied. To this end a model that predicts coupled cross-flow – in-line

efficiently describe both the upper and the lower branches of free vibration

vibrations of a free spanning suspended floating pipeline was developed.

experiments. The improved Ogink-Metrikine model was found to better

For the vortex lift force acting on the pipe the models that have been

describe the main characteristics of free vibration experiments over a wide

shown to match better with free and forced vibration measurements of

range of mass ratios. Moreover, it succeeded in describing the jump from

elastically mounted rigid cylinders have be considered. The system has

positive to negative values of the vortex lift force coefficient in phase with

been solved in the time domain and model results were presented over a

the body acceleration and the modelling of the width and height of the

range of flow velocities considering different boundary conditions.

region with negative vortex lift force coefficient in phase with the body velocity. The model successfully predicts two regions of negative values of

Results

vortex lift force coefficient in phase with the body velocity, separated by a

In both systems of equations the frequency power spectra of the cross-

small region values, just as in the experimental results.

flow oscillation at the midpoint of the pipeline, showed that vibration occurs in well-defined frequency bands for certain reduced velocity ranges.

Student: N.E. Oikou Thesis Committee: Prof.dr. A.V. Metrikine, Dr.ir. W.T. van Horssen, Ir. H. Hendrikse, Ir. R.H.M. Ogink

For further information, please contact the section of Building Engineering tel. 015-2784578 Email: [email protected]

20 | Master’s Theses March 2012

2

Structural Engineering

Torsion in ZIP bridge system

In skew bridges torsion occurs. This leads to a substantial amount of reinforcement stirrups. Kassahun Minalu already did research to torsion in bridge decks with different types of finite element models. The question when torsion cracks will really occur is still unanswered. This question is the main subject of this research. The focus of the research is on a skew bridge with a skew angle of 45 degrees. The bridge is made using the ZIP girders made by the company Spanbeton. In that skew bridge the largest torsional moments will occur. Beside that also a straight bridge is analysed, the torsional moments in a straight bridge are always lower than in a skew one under the same loading. The loads of Eurocode 1991-2 are used. Two important load configurations governing for torsional moments and shear force are used: a configuration which is used in daily practice at Spanbeton and a configuration developed by Minalu. An attempt is made to model the whole bridge including physically non-linear behaviour with the program ATENA 3D to analyse the torsion effects. With the current state-of-the-art modelling technology that appeared to be impossible. For that reason a simplified model is developed to simulate the stress state and cracking in one ZIP girder. It was concluded that it is important to use more quadratic elements over the thickness of the web to obtain correct torsion shear stresses. From the simplified model it is concluded that, despite some shortcomings, clearly a substantial length at the ends of the girder is uncracked.

To be sure that the computer model is correct a calculation of the principal stresses is carried out at the ultimate limit state. The stresses due to prestressing, own weight and the weight of the fresh poured concrete can be calculated by hand. The calculation of the force distribution of the loads on the deck can be carried out using finite element methods. Scia Engineer (orthotropic plate model) and ATENA 3D (volume elements) are used for this calculation. Especially the determination of the torsional moments from ATENA by using an analysis of the rotations is interesting. This calculation results in the torsional moments, bending moments en shear forces acting on the ends of the girder.

The main conclusion of this research is that in ultimate limit state no cracking will occur in the end of the considered girder in the skew bridge. This means that only the minimal shear reinforcement must be applied and the full torsional stiffness can be used in finite element calculations. A practical method to check this for other bridges using ZIP-girders is proposed.

Student: E. van Vliet Thesis Committee: Prof.dr.ir. J.C. Walraven, Dr.ir. C. van der Veen, Dr.ir. P.C.J. Hoogenboom, Ir. C. Quartel, Ir. L.J.M. Houben For further information, please contact the section of Building Engineering tel. 015-2784578 Email: [email protected]

21 | Master’s Theses March 2012

2

Structural Engineering

Feasibility of using activated paper sludge recycled minerals As a partial cement replacement Global warming, which is mainly caused by mankind with the emissions of greenhouse gases, is nowadays one of the major topics in the world. The reduction of these greenhouse gas emissions has become a primary focus of environmental organizations and the government in many countries. Since Portland cement production is accompanied by a significant CO2 emission, which is a principle greenhouse gas, it is useful to look for ecological alternatives of cement. The use of thermally activated paper sludge minerals (Top-Crete) as ingredient for artificial building materials is studied. By calcination and dehydration of paper sludge, which is a by-product of recycled paper waste, a nontoxic mineral with a highly pozzolanic activity is formed. Besides the pozzolanic activity this mineral also shows hydraulic potential. The replacement of cement with these activated minerals (Top-Crete) is proposed to reduce the environmental burdens that are associated with the concrete productions and with the disposal of paper sludge waste. The main goal of this study was to examine the feasibility of Top-Crete (TC) as a partial replacement for cement, and especially as a leverage to use more supplementary cementing materials, such as fly ash.

Both physical and chemical effects of Top-Crete on concrete properties were studied experimentally. The results show that the addition of Top-Crete leads to a decrease in workability, setting time, bending strength, compressive strength and calcium hydroxide content. The greater water demand of Top-Crete is mainly attributed to its large specific surface area and high pozzolanic activity compared to that of fly ash and Portland cement. The results indicate that partial replacement of cement with Top-Crete decreases chemical shrinkage with 25% or more, particularly at higher replacement levels. It was also observed that the replacement of Portland cement by 5% Top-Crete substantially decreases the pore structure of the blended cement paste compared to that of the control paste.

Student: M. Ahammout Thesis Committee: Prof.dr.ir. K. van Breugel, Dr. G. Ye, Dr.ir. S.A.A.M. Fennis–Huijben, B.M. Piscaer, Ir. L.J.M. Houben For further information, please contact the section of Building Engineering tel. 015-2784578 Email: [email protected]

22 | Master’s Theses March 2012

2

Structural Engineering

Progressive collapse in design of bridges

The Eurocode requires that a structure shall not be damaged to an extent disproportionate to the original cause, but it provides no guidance at all for the design of bridges. It leaves bridge engineers with questions on the definition of disproportionate, on the maximum level of acceptable risk and on how to deal with malicious attacks such as impact and explosions.

Minneapolis, USA The main objective of this report is to present a general design approach for bridges, in order to efficiently reduce the potential of progressive collapse. This has been done by carrying out an extensive literature study, creating a framework to describe the reliability of structural systems and applying the framework in a case-study. Design requirements of many codes of practice are mainly based on load and resistance models for structural elements. Every element of a structural system should be checked to have a lower probability of failure than prescribed. In addition, provisions are needed to specifically safeguard the reliability of the system, among which is robustness. A robust structure is defined as a structure that is able to withstand events like fire, explosions, impact or the consequences of human error, without being damaged to an extent disproportionate to the original cause. The design strategies to increase robustness are local damage control and spread of failure control. The latter involves the modelling of collapse scenarios from initial states of

local damage and thus analysing the behaviour of structural systems. The efficiency of risk mitigation measures, such as providing specific local resistance and providing alternative load paths, is evaluated by comparing the costs of a measure with the potential reduction of the risk of failure. The consequences of a bridge collapse may include a large number of fatalities, major social impact and high economic damage. This report shows that the probability of a (progressive) collapse can best be calculated in two steps: the probability of component failure and the probability of system failure given component failure. These are coupled to consequences: direct risk is defined as the cumulative risk of all direct damage states (e.g. component failure) and total risk is defined as the cumulative risk of all total damage states. Distinguishing between the direct risk and the total risk makes it possible to indicate the sensitivity of a structure to local failure, by taking the economic consequences as a measure for the proportionality between damage states. The robustness should be measured by selecting the disproportionate damage states and comparing the risk of disproportionate damage to a norma-tive monetary value. The presented design approach has been implemented on a casestudy. It includes the modelling of a structure, failure mode analysis, risk analysis, design optimisation and a calculation of robustness. The main conclusion of this report is that potential damage should be separated between direct damage and indirect damage in a progressive collapse analysis. An engineer is then able to better understand the effects of risk mitigation measures on the reliability and robustness of a structural design. The presented methodology can be used as a tool to evaluate risk mitigation measures and thereby efficiently reduce the potential of progressive collapse of bridges. However, further research is needed to validate the proposed robustness index and to account for dynamic effects in the model.

Student: S. van Wijk Thesis Committee: Prof.ir. A.Q.C. van der Horst, Prof.drs.ir. J.K. Vrijling, Dr.ir. C. van der Veen, Ir. L. Groenewegen (BAM Infraconsult) For further information, please contact the section of Building Engineering tel. 015-2784578 Email: [email protected]

23 | Master’s Theses March 2012

2

Structural Engineering

Interaction between plate and column buckling

Dimensioning and verification of steel structures is often governed by the demands for stability and the plastic capacity of the material is not fully utilized. There are a few different forms of instability such as column buckling, lateral-torsional buckling and plate buckling. Interaction of plate and column buckling has not been extensively studied before and that is the main goal of this master thesis. In present verification codes in The Netherlands it is allowed to separately calculate the effects of both and then combine them in a certain way. Question is whether this is indeed correct. Analytical calculations have been done on an I-shaped column to derive the theoretical buckling load combining the effects of plate and column buckling. Also calculations have been done using a finite element method. For some types of cross-sections the results are significantly different compared to the verification regulations. This is for uneconomic cross-sections with a large area of the web compared to the area of the flange. The difference can be up to 20% of the bearing capacity. In general a designer is free to design any sort of structure. After that the structure should be verified for structural safety using the regulations. These regulations should either provide the correct verification regulations or inform that a certain type of structure is outside the scope of the regulations. Neither is done in the current verification regulations. A formula is developed to calculate the reduced bearing capacity for this type of cross-sections.

A design recommendation has been done on how to design a class 4 cross-section. It is not very efficient to include longitudinal stiffeners to the web for the effective cross-section method. Only the effective area of the web is increased which is in general small and for bending moments also close to the centre of gravity. A design tool is developed which checks a class 4 cross-section according to the verification regulations in NEN-EN1993-1-5. The tool can check I cross-sections as well as a box or a cross-section. Longitudinal stiffeners to the web, through decks and concrete toppings can be added.

Student: A. van Ham Thesis Committee: Prof.ir. F.S.K. Bijlaard, Ir. R. Abspoel, Dr.ir. P.C.J. Hoogenboom, Ir. J.H. Reusink, Ir. L.J.M. Houben For further information, please contact the section of Building Engineering tel. 015-2784578 Email: [email protected]

24 | Master’s Theses March 2012

2

Structural Engineering

Most cost effective connection between arches Blalobridge

Introduction Common practice for arch bridges is to use almost the same diameter for the connecting girders between different arches as the diameter of the arches themselves. There are different reasons for this, one of these reasons is that it saves calculation time because these girders will not be the critical component of the bridge.

Problem definition The objective of this thesis is to design the most cost effective connection between the arches for the planned arch bridge in Zwolle, the Blalobridge. In the design all possible forces acting on the connection should be taken into account. This design has to be compared with the reference variant calculated by ARCADIS.

of these connections proved to have a large influence on the calculation results. The next step was to design eight variants with a diameter varying between 610 mm and 193.7 mm and a wall thickness varying between 25 mm and 8 mm. These variants have been checked according to the Eurocode standards regarding maximum stresses and (local) stability. The result was some minimum cross sections that still passed the checks of the Eurocode. The results of the check of these variants are used to create sixteen more variants with a diameter of 323.9 mm and 298.5 mm and a wall thickness varying between 25 mm and 7.1 mm. The next step was to calculate the costs regarding the most favourable design variant and the reference variant to be able to compare the results. A distinction can be made in costs concerning the purchasing of the material, the fabrication, conservation and maintenance. Besides these costs, costs will be made concerning transport, guidance and engineering.

Conclusion and recommendation

Research First, research has been done into the forces acting on the arch bridge, the mechanics of the arch bridge and the mechanics involved when using circular hollow sections. This research resulted in an understanding of the mechanics of arch bridges, design rules regarding the connection between connecting girders and arches and design rules regarding fatigue behaviour of circular hollow section joints. Especially the connection strength, connection stiffness and fatigue behaviour

A variant, with a connecting girder 298.5-16 at the end portals to ensure stability and connecting girders 298.57.1 at the other positions to ensure a sufficient fatigue lifetime and static strength has been proven to be the most slender solution. The total costs of the reference connecting girders were about € 49,416 while the total costs of the most favourable design variant were about € 12,580 resulting in a reduction of cost of around € 36,836. Besides this small reduction of building costs, the reduced connecting girders could also provide an aesthetic improvement because of the lighter and more open structure. More research is recommended in out-of-plane buckling behaviour because of large differences between calculation methods. Besides this, more advantages could be achieved by reducing the arch diameter and/or using another connection system between the arches.

Student: H.R. van der Land Thesis Committee: Prof.ir. F.S.K. Bijlaard, Prof.dr.ir. J. Wardenier, Dr.ir. M.A.N. Hendriks, Ing. H.M.F. Beertsen, Ir. L.J.M. Houben

For further information, please contact the section of Building Engineering tel. 015-2784578 Email: [email protected]

25 | Master’s Theses March 2012

2

Structural Engineering

Feasibility of Tall Timber Buildings

Advantages of timber as a building material are: small dead weight, good thermal characteristics and in some cases low overall building costs. Nature has created large cantilever structures of 150 m high in the form of eucalyptus trees. History shows furthermore manmade structures as timber radio towers of 190 m high and wooden religious structures of almost 1000 years old, towering 67 m in the air. The most recent modern tall timber building is about 29 m high, contains nine storeys, is located in London, UK, and is called “the Murray Grove Tower”. What is discussed above leads to the question: “What is the height limit for tall timber buildings”. To answer this question, the objective of this thesis is twofold. The first objective is to determine the influence factors on the height of timber buildings. The second objective is to create proof through analysis of a case study design of at least 100 m high within a determined set of boundary conditions.

In the second part of the thesis these proposed solutions are investigated. Four variants where created consisting of a set, corresponding to the geometry of the proposed types of bracing and associated joint solution. Three-dimensional models where created with finite element software of these variants. Of these models, parameters are modified in order to investigate: the influence of the joint stiffness, the building core stiffness, and the support stiffness on the global behavior. The investigation on the global behavior of the systems focuses on the deflection at the top, the development of bending moments within members and the dynamical behavior. An optimisation of the cross sections of structural members was also conducted in order to investigate the competition of feasibility between variants. The fire behaviour of variants was determined for a combination of structural solutions, fire safety concepts and fire suppression measures.

A preliminary study was conducted to realise the first objective. This preliminary study contains a problem analysis in which the influence factors are determined and a definition is found for tall timber buildings. The main influence factors are part of architectural requirements, structural issues, fire safety and building physics. The influence factors are quantified to achieve the highest potential.

The deflection at the top of the timber building satisfies the limits of the building code for all variants. It was derived that the deflection at the top of the building is for 14% to 20% due to the joint stiffness, for 39% to 56% due to the stiffness of the cross laminated timber building core and for 16% to 23% influenced by the stiffness of the foundation of concrete bored piles. The results of the dynamical analysis are strongly dependent on the used method. The dynamic behavior of some combinations of structural system and calculation method does not satisfy the requirement stated in the Dutch standard, NEN 6702.

This deduction of influence factors resulted in a set of boundary conditions and proposed solutions. First a universal floor plan was designed as a starting point. A minimum wall-window ratio of 15% and a building slenderness of 1:4 were set as architectural boundary conditions. The material applied to the load bearing structure was chosen to consist of timber laminations of strength class D70 which has a positive effect on the structural and fire characteristics. The proposed stability system consists of a braced tube-in-tube structure. The investigated types of bracing are the Diagid geometry, simple diagonal bracing and a solid timber shear wall bracing. To realize a fire safe design, relevant objectives are satisfied through the choice of a fire concept, in combination with fire suppression measures, resulting in compartment burn out.

It is concluded that a tall timber building structure of 112 m high is possible on a fundamental level. Several structural systems can be applied in combination with an appropriate fire concept.

Student: S.G.C. Timmer Thesis Committee: Prof.ir. R. Nijsse, Ir. G.J.P. Ravenshorst, Ir. K.C. Terwel

For further information, please contact the section of Building Engineering tel. 015-2784578 Email: [email protected]

26 | Master’s Theses March 2012

3. Civil Engineering theses

Hydraulic Engineering

3

Hydraulic Engineering

Primary dikes in Limburg

Overview differences In this study the differences between the primary dikes in Limburg and in the rest of the Netherlands are mapped and the consequences a possible removal of these differences are investigated. These differences are diffferences in: safety standard, determination design water levels, wind set-up, floodability, freeboard, robust design, expandability, wave run-up and wave overtopping, hydraulic structures and pipelines.

Conclusions Formation of the differences Limburg has lower safety standards than the rest of the Netherlands. This standard is not based on a detailed cost-benefit analysis and safety risk.

Other differences between the primary dikes in Limburg and the rest of the Netherlands In addition to the floodability requirement, doubt rises about the remaining differences in the primary dikes in Limburg and the rest of the Netherlands.

Hydraulic boundary conditions It is not required to keep to the old hydraulic conditions of the HR2001, because the primary dikes in Limburg according to the ‘Maasmodellen 2020’ meet the water levels of the ‘Bestuursovereenkomst 2010’ . Determining the recent conditions (TMR2006) will not cause adverse effects on the high water levels mentioned in the ‘Bestuursovereenkomst 2010’.

Influence of actors

Limburg primary dikes The design height of the primary dikes in Limburg according to the ‘Bestuursovereenkomst 2010’ are high enough based on an analysis using updated assumptions.

Downstream effects

The informal reporting structure differs from the formal reporting structure. The reporting structure also differs from the financial responsibility. Directoraat-Generaal Water is financially not in the top of the hierarchy, but he has authority on the reports.

The model simulations for the situation in 2020 does not result in a water level rise downstream in NorthBrabant and Gelderland, not even if the safety standards in Limburg are increased up to 1 / 1250 per year.

Floodability requirement in Limburg Based on this study it can be concluded that maintaining the existing floodability requirement in Limburg is not necessary, because the water level downstream does not increase.

Student: L.M. Groendijk Thesis Committee: Prof.dr.ir. H. J. De Vriend, Dr.ir. E. Mosselman, Dr. J.H. Slinger, Ir. L Loomans, Ir. D.G. Meijer

For further information please contact the section Hydraulic Engineering, 015-2783348 Email: [email protected]

28 | Master’s Theses March 2012

3

Hydraulic Engineering

Flooding and sediment management on the Koshi alluvial fan

Introduction The flood of the Koshi River in 2008 is the motive to execute this study. This flood is described as one of enormous proportions, a disaster which severely influenced the life of hundred thousands of people in Nepal and millions of people in India.

Large scale morphological changes This study investigates the natural aggradation of the river system and the influence of the barrage on the river system. The occurring hydraulic and morphologic processes during the flood of 2008 and the influence of this flood on the river system are studied as well. Since reliable data about many aspects of the Koshi River are not available, it was decided to make a one-dimensional model, to simulate the large scale morphological and hydrodynamic processes and in addition to gain insight in the one-dimensional processes, such as retrogressive erosion and the propagation speed, during the flood of 2008.

The braided channel pattern and measures applied To be able to test the effectiveness of the recurrent measure to manage the sediment, a 2DH-model of the Koshi River is developed. Before this measure can be tested, smaller scale hydrodynamic and morphodynamic processes of the Koshi have to be modelled and explained. Firstly, an effort is made to model the braided plan form of the Koshi River. Furthermore, different settings for important parameters are applied, to determine the sensitivity of the model. After this, the narrowing of the river with recurrent measures is tested; by the application of porcupines in certain channels. Also narrowing with permanent structures is performed. The results can be seen as exploratory. Koshi, braided river, sediment, morphology, flooding

Promising measures Insight in the hydrodynamic and the morphological processes in the Koshi River are also of great importance for understanding the shifting behaviour of the river and to perform suitable measures. Closely related to this shifting behaviour is the high sediment load of the river. A key factor in the flooding problem approach is a strategy to deal with the sedimentation. This is a very challenging task due to the huge amounts of sediment and since the sediment is infertile, it has no utility. Only a small percentage is used as construction material. An exploration for possible technical solutions is performed. The most promising measure is the construction of sleeper dikes, to reduce the risk of flooding and narrowing the Koshi River with recurrent measures, to manage the sediment.

Student: E.M. Hooning Thesis Committee: Prof.dr.ir. H.J. de Vriend, Dr.ir. E. Mosselman, Dr.ir. C.J. Sloff, Dr. T.A. Boogaard, Ir. G.J. Klaassen For further information please contact the section Hydraulic Engineering, 015-2783348 Email: [email protected]

29 | Master’s Theses March 2012

3

Hydraulic Engineering

Erosion in the tide-influenced Rhine-Meuse delta Erosion processes and bed level maintenance strategies

Due to the closure of the Haringvliet in 1970 as part of the Delta works and the opening of the Beerdam in 1997, the course of the tidal flow in the RhineMeuse delta has changed. The tidal flow from and towards the Haringvliet is now completely taking place through the branches that connect the Haringvliet with the Nieuwe Maas and Nieuwe Waterweg. This causes these branches to erode by the increase of the tidal prism. The erosion problems occur in the central parts of the Rhine-Meuse delta, which, amongst other rivers, includes the rivers Spui, Oude Maas, Noord and Dordtsche Kil. The presence of sand, clay and peat layers in the branches causes the erosion mechanism to be rather complex. The alternation of sand and clay layers in the area causes the erosion to be nonuniformly distributed, resulting in deep local scour holes. The goal of this research is to determine an adequate maintenance strategy for the problem area. In order to do so the erosion processes are modeled in an existing Delft3D model

for the whole Rhine-Meuse delta. The uncontrolled character of this strategy can also cause navigation nuisance.

In this study, the morphodynamics in a depth averaged model, covering the Dordtsche Kil and a part of the Oude Maas, are calibrated in such a way that it quantitatively fits the existing long term erosion trend and that the qualitative processes of scour in the model simulations comply with the erosion occurring in reality. This is achieved by implementing multiple sediment layers simulating a bed topography where clay layers and local sand packages alternate.

It is strongly recommended to investigate the effects and possibilities of opening the Haringvliet sluices further. Further research should also be done with the extension of the Delft3D model to the Spui river, the downstream part of the Oude Maas and the Noord. Since the numerical model can become (even more) extensive with the implementations of 3 more domains, much more insight in the problems can be obtained with the interaction of the different eroding branches in a Delft3D model.

The other type of maintenance strategies considered is the reduction of erosive flow in the system. A situation where the Haringvliet gates are always opened, even during high tide, leads to a remarkable reduction in erosion. The scour holes still undergo erosion, but at a slower rate, and the erosion of the clay layer decreases to a negligible amount. A combination of fixing scour holes and opening the Haringvliet gates is also considered, which solves the problem for long-term erosion and the local scour, but comes at a high cost to implement. Besides in the Oude Maas, the erosion in the Spui branch is also alarmingly severe. In order to reduce erosion in this river branch, an option is to close it off. This causes the flow velocity in the Oude Maas to increase with approximately 10% and to reduce the flow velocity in the river Spui by half.

Subsequently modeling a variety of possible maintenance strategies has shown that several effective strategies are possible to deal with the erosion problems. Two strategies are suggested regarding the shortage of sediment in the system. The best way to deal with the local scour problems is to prevent further scouring of existing holes by fixation with riprap. Continuous nourishment in scour holes prevents the holes from scouring any further and moreover provides a solution for the long-term problem due to the fact that out flowing sediment diffuses and spreads out over the whole length of the river. A disadvantage of this strategy is the future obligation of continuous maintenance and monitoring

Student: T. Smits Thesis Committee: Prof.dr.ir. H.J. de Vriend, Dr.ir. C.J. Sloff, Dr.ir. E. Mosselman, Dr. G.J. Weltje

For further information please contact the section Hydraulic Engineering, 015-2783348 Email: [email protected]

30 | Master’s Theses March 2012

3

Hydraulic Engineering

The Lagos coast Investigation of the long-term impact of Eko Atlantic City

Abstract The Lagos coast has been suffering high rates of erosion since the construction of three harbour moles, i.e. the West Mole, East Mole and the Training Mole, between 1908 and 1912. The moles were constructed to stabilize the harbour entrance channel, located at the tidal inlet connecting the Lagos Lagoon to the South Atlantic Ocean. West of the West Mole, which is updrift, the Lighthouse Beach is located and east of the East Mole the Bar Beach is positioned. The persistent, high-energy swell waves, propagating to the coast from a south-southwest direction, induce a mean eastward longshore sediment transport.

the coastal system. As sediment is extracted from the longshore current, the volume of sediment bypassing the East Mole is limited. Therefore, the downstream Bar Beach erodes, to provide for a sediment source for the longshore sediment transport.

Future morphological development

The Eko Atlantic City project Over the last fifty years, already a lot of erosion mitigation measures have been undertaken at the eroding Bar Beach, of which the most frequently applied one is the performance of sediment nourishment on the beach. However, none of the measures proved completely successful. So, to provide for a permanent erosion mitigation measure and to create residential and commercial area for circa 400,000 people, the Eko Atlantic City project has been initiated in 2008 by the private project developer South Energyx Nigeria Ltd. (SENL). In front of the eroded coast, approximately 9 km² of land will be reclaimed and protected by a revetment.

Conceptual model In this study the long-term and large-scale morphological behaviour of the Lagos coast is investigated. Subsequently, the long-term morphological impact of the Eko Atlantic City project is assessed. First, a conceptual model is created, in which the historical development of the coast is discussed. It is concluded that the longterm morphological behaviour of the coast downstream of the inlet is determined by two main factors: sediment accumulation at the West Mole and sediment import into the tidal inlet and the lagoon. The sediment import is induced by disturbance of the morphological equilibrium of both the tidal inlet and the lagoon, due to sea level rise and dredging activities. The sediment accumulation at the West Mole and the sediment import into the tidal inlet and the lagoon both function as a sink in

Further, using the numerical simulation model Unibest, the long-term morphological impact of Eko Atlantic City is investigated. It is concluded that the construction of Eko Atlantic City will not change the total erosion volumes occurring downstream of the inlet. However, as the revetment of the project retains the coast, the erosion will be shifted towards downstream. Downdrift of the project, the erosion rates are locally relatively high. Therefore, mitigation measures are recommended. Since at the Lagos coast already over fifty years nourishments have been performed, it will be a suitable option to apply a nourishment scheme in the future as well. Also a monitoring strategy is recommended to monitor the coastal development downstream of the project and to instruct coastal protection management actions to be implemented.

Student: K.M. van Bentum Thesis Committee: Prof.dr.ir. M.J.F. Stive, Dr.ir. M. van Ledden, Dr. J.E.A. Storms, Ir. C. Hoyng, Ir. A.P. Luijendijk

For further information please contact the section Hydraulic Engineering, 015-2783348 Email: [email protected]

31 | Master’s Theses March 2012

3

Hydraulic Engineering

Impact of re-surfacing groins on hydrodynamics and sediment transport Re-surfacing groins at the Delfland Coast Due the coastal protection program along the Dutch coast, the groins that first defended the coast against erosion, are now covered under sediment. Due to erosion the covered groins will resurface however. The objective of this study is to investigate the effect of the resurfacing groins on the hydrodynamics and sediment transport.

Modeling A schematized model is made to reduce effects due to a complex bathymetry and to get a clear view of the occurring processes. Three profiles are schematized at a suitable location based on the 1990, 2009 and 2010 Jarkus transects. Also a test case is modeled with a constant slope to get a view on the effect that groins have on several hydrodynamic properties and transports. The effects due to the bathymetry and the groin can now be separated.

Results From this follows that the groins do not affect the alongshore current velocity significantly when the groins are relatively small, in the order of 50 meters or less. The offshore directed currents are considered more dangerous and are present and increasing with increasing groin length, although they are also small when groins are relatively small. When the groin length increases to 150 meters, both the longshore and the offshore currents become significantly larger. In the test case the increase in alongshore velocity is around 15% compared to small or no groins. The increase in current velocity depends largely on the bathymetry and the position of bars however. The sediment transports decrease quite constantly with increasing groin length when the foreshore has a constant slope, in case of a profile with bars the decrease of transport may not be constant anymore. In the schematized cases the sand transport in 1990 with groins of 140 meter is in the order of 50% smaller than in the 2010 situation without groins. Scour holes can increase the offshore directed transports and velocities, but further research is needed here.

Student: A. Hendriks Thesis Committee: Prof.dr.ir. M.J.F. Stive, Ir. P.K. Tonnon, Ir. A.P. Luijendijk, Ir. M.A. de Schipper, Ir. P.B. Smit

For further information please contact the section Hydraulic Engineering, 015-2783348 Email: [email protected]

32 | Master’s Theses March 2012

3

Hydraulic Engineering

Probabistic Modelling of Extreme Beach erosion using XBeach.

The long series (>30 year) of measurement data of erosion events at Narrabeen beach (NWS, Australia) provides insight in erosion volumes and their return periods in this area. The aim of this study was to replicate these data using XBeach in order to assess the validity of both the Joint Probability Model (JPM) and XBeach on beaches such as Narrabeen. In this study, a large number of different storms were simulated using XBeach. The probability and thus return period of the resulting erosion volumes were determined using the JPM. XBeach was calibrated against two individual erosion events, one at Narrabeen beach and one at Hasaki beach (Japan). The best fit for the Narrabeen beach, obtained using a stationary mode, led to an overestimation of erosion volumes at lower return periods (< 3 year) but fell within the boundaries implied by a 95% confidence interval of the measurement data for higher return periods.

Return Period of Erosion Volumes using XBeach and 95% confidence interval based on 1000 *10 4 simulations (red line and red shaded area). Analysis done with measured storm-frequency of period 1976-2006. Compared to JPM method using K& D (orange line) with 95% confidence interval indicated by the orange shaded area, and SBEACH (blue line) with 95% confidence interval indicated by the blue shaded area (after Callaghan et al. 2008a end 2008b).The gray lines represent the 95% confidence interval of the data (Consecutive volumes method). When calibrated against the erosion volumes with low return periods (<2 year), XBeach slightly underpredicted the erosion volumes at higher return periods. Depending on the method of determining confidence levels, the results were outside or well within the confidence interval of the measurements. This could suggests that this method is a valid way to predict erosion volumes and their return periods, in cases where long term erosion volumes measurements are absent.

Student: M. Riesenkamp Thesis Committee: Prof.dr.ir M.J.F. Stive, Dr. R.W.M.R.J.B. Ranasinghe, Dr. P.H.J.A.M. van Gelder , Drs. F. Baart , Ir. C. den Heijer, Dr. D. Callaghan For further information please contact the section Hydraulic Engineering, 015-2783348 Email: [email protected]

33 | Master’s Theses March 2012

3

Hydraulic Engineering

Edge scour around an offshore wind turbine

Wind energy has experienced an enormous growth in the last years and is becoming more and more popular as an alternative for conventional power. Large growth numbers are also expected for the coming years, for onshore as well as for offshore wind energy. The first offshore wind park in The Netherlands is Offshore Wind park Egmond aan Zee (OWEZ). In order to reach the large growth numbers for the offshore wind energy, some engineering challenges need to be overcome. One of these challenges is the bed protection around the turbine foundations. Surveys of the bed levels around the wind turbine foundations in OWEZ have shown that just beyond the scour protection edge scour develops. This can cause damage to the electricity cables buried in the bed. A damaged electricity cable results in down time of the wind turbine and the wind turbines connected to it further in the string. The required burial depth of the cables is therefore governed by the location and depth of the edge scour hole. The present exploratory study revealed that more research is needed to compute edge scour development correctly with the software package Delft3D-Flow. However, even if the model results in Delft3D-Flow would be perfect, considerable or even unacceptable computational times need to be overcome. Therefore, a less time consuming method to calculate the edge scour depth would be very valuable. In order to develop such a method for calculating edge scour depth, the following objectives have been studied: 1. Gain insight in the hydrodynamic and morphodynamic processes around the foundation of an offshore wind turbine with bottom protection, focussing on edge scour. 2. Explore the possibilities of applying Delft3D-Flow for modelling the hydrodynamic and morphodynamic processes around the foundation of an offshore wind turbine with bottom protection, focussing on edge scour. 3. Develop a model to predict the depth and rate of edge scour around the foundation of an offshore wind turbine.

The research reveals that tidal asymmetry is of major concern in the development of edge scour. Edge scour develops mainly downstream of the wind turbine for the dominant tide. In addition, lee-wake vortices downstream the wind turbine play an important role in the formation of the edge scour holes. The performance of Delft3D-Flow is rather poor in this specific situation. A lack of resemblance between the bed levels computed with Delft3D-Flow and the measured bed levels in OWEZ exists. Most likely this is due to mediocre performance of the two-dimensional model with respect to the hydrodynamics in this specific situation. In order to calculate the edge scour depth, the Edge Scour Prediction Model (ESPM) has been developed. This is a model based on mathematical relations of development towards an equilibrium in time and empirical relations for the equilibrium edge scour depth and characteristic timescale. Results of the Delft3D-Flow model are applied as input for the ESPM. The ESPM has proven to reproduce the edge scour depth as function of time in OWEZ reasonably well. In addition, it can be a valuable tool for a first impression of the edge scour depth in new designs at other locations.

Student: E. Simoons Thesis Committee: Prof.dr.ir. M. J. F. Stive, Ir. H. J. Verhagen, Ir. M. L. A. Segeren, Ir. T. C. Raaijmakers, Ir. A. P. Luijendijk, Dr. Bai W. For further information please contact the section Hydraulic Engineering, 015-2783348 Email: [email protected]

34 | Master’s Theses March 2012

3

Hydraulic Engineering

Process-based modelling of morphological response to submerged breakwaters

Submerged breakwaters (SBWs) are becoming increasingly popular as alternative coastal defence system due to the lack of impact on beach amenity and aesthetics compared to common emerged beach protection measures. However, the recent significant amount of failing SBWs resulting in additional shoreline erosion reported in [Ranasinghe and Turner 2006], indicates the importance of understanding the driving processes of salient development before routinely adopting SBWs in practice. The main objective of this thesis is to gain more insight into single shore-parallel detached SBW induced hydrodynamic processes driving morphological changes. In order to study SBW induced hydrodynamic conditions resulting in morphological response, a depth-averaged Delft3D model is used. By online coupling of Delft3DFLOW and SWAN, the wave-current interaction is accounted. To exclude site-specific conditions, an idealized approach is used, including an alongshore uniform beach profile and shore normal short wave forcing. For this idealized situation, a sensitivity analysis of numerical parameters is performed, as well as a validation on individual SBW induced processes based on published literature.

As a result, a computationally efficient depth-averaged Delft3D model is obtained, which is capable of simulating SBW induced processes accurately compared to published literature. From the idealized simulations, more insight is given in two distinct SBW induced processes driving morphological response. These processes reducing nearshore water level set-up are the spatial distribution of wave forcing (commonly referred as wave sheltering effect) and the momentum balance between wave forcing and bottom stresses over the SBW. In addition to the parameters presented in [Ranasinghe et al. 2010], the breakwater roughness and directional spreading of waves are important parameters to take into account when constructing SBWs. Morphological simulations confirm the relation between the hydrodynamic processes described and the morphological response to SBWs. The ability of Delft3D to simulate morphological response to SBWs, enables a powerful numerical tool for future studies on SBW induced (morphological) processes.

By examining the cross- and alongshore momentum balance for a variety of results from numerical simulations only changing alongshore length and offshore distance of the SBW, dominant SBW induced alongshore differences in water level and resulting currents are explained in detail. In addition, SBW design parameters are studied using the same momentum balances. Besides offshore distance, alongshore length of the SBW and directionality of the incoming waves, these include the crest width, crest height, incoming wave height and breakwater roughness. To confirm the findings from the hydrodynamic analysis as the important driving processes of SBW induced morphological changes, additional morphological simulations are included and morphological SBW induced response is compared to initial hydrodynamic conditions.

Student: Thesis committee:

R.J. Vlijm Prof.dr.ir. M.J.F. Stive, Associate professor Dr. R. Ranasinghe, Ir. A.P.Luijendijk, Dr.ir. G.J. de Boer

For further information please contact the section Hydraulic Engineering, 015-2783348 Email: [email protected]

35 | Master’s Theses March 2012

3

Hydraulic Engineering

Dune erosion near sea walls XBeach validation

Storm impact on a dune-dike system During a storm dunes erode and provide sediment to the beach. The foreshore rises and the wave height decreases. Subsequently the wave-induced water level setup increases. Seawalls do not erode. The waves in front of the seawall remain high throughout the storm and the wave-induced water level setup hardly changes. Over a dune-dike connection a water level gradient drives a current which transports sediment from the dunes to the seabed in front of the seawall. The loss of sediment to the dike causes the foreshore of dunes near the connection to rise slower resulting in more erosion. Obliquely incident waves generate a longshore current which transports sediment along the shore. In front of a seawall the velocity and transport capacity of the longshore current is limited. In a dune transect the the transport capacity of the longshore current is larger. Subsequently there is a longshore gradient in the transport capacity in the transition zone. The amount of additional erosion near structures depends on the angle of wave incidence w.r.t. the shore. Dunes situated downstream of the connection experience a significant increases in erosion. Near the upstream connection sediment is deposited on the seabed in front of the structure. Sediment will pile up against the structure resulting in less erosion near the connection.

Experiments in the Delta Basin The influence of structures on dune erosion was investigated in a series of experiments. They were carried out with normally incident long-crested waves and were

aimed at 4 different connections between a dune and a structure. Two configurations of dunes and structures were investigated. Each configuration was tested with 2 different wave periods Tp. The experiments proved the development of additional erosion near structures. The connections investigated in the experiments were: The connection between a dike and an unprotected dune, The connection between a dike and a dune that is protected by a dune revetment, A breach in a dike with a body of sand, A breach in a dune revetment.

Model-data comparison The measurements of the experiments are compared with XBeach predictions. In XBeach the erosion in a dike breach is a function of the breach width and the wave period. The erosion increases for a smaller breach width. The breach erosion increases for an increasing wave period. XBeach underestimates the erosion above the dune revetment. To erode the dunes above the revetment wave runup is an important process. Currently XBeach only simulates long wave runup. The erosion in the revetment breach is predicted well. For experiments V1 & V3 with a wave period of Tp = 2.07 seconds the predictive capabilities of XBeach in dune sections are very good. The performance of XBeach for experiments V2 & V4 with Tp = 1.55 seconds is relatively good. The peak frequency has a relatively large influence on the amount of dune erosion predicted by XBeach. The effect of the wave period for 2DH models with a large depth scale (nd = 60) is not properly simulated by XBeach.

Student: B.B. de Vries Thesis Committee: Prof.dr.ir. M.J.F. Stive, Dr.ir. J.S.M. van Thiel de Vries, Dr.ir. A.R. van Dongeren, Ir. P.F.C. van Geer, Ir. P.B. Smit For further information please contact the section Hydraulic Engineering, 015-2783348 Email: [email protected]

36 | Master’s Theses March 2012

3

Hydraulic Engineering

Flexible scour protection around cylindrical piles

This research focuses on the behaviour of a granular scour protection around piles when the bed is subjected to bed degradation. Furthermore, engineering guidelines are provided to account for bed degradation in the design of the initial scour protection. To address the behaviour of the protection, a physical model is used and to obtain the engineering guidelines, a theoretical approach is used which includes the phenomena that are observed during the physical model tests. As stated by many authors [Breusers et al., 1991; Chiew, 2004; Melville et al., 2000], a granular scour protection around a pile can fail due to several mechanisms. In clear-water conditions these mechanisms include shear failure, winnowing and edge scour and in live-bed conditions two other mechanisms can be added, namely bed degradation and bed form induced failure. This research focuses the effect of the bed degradation mechanism on the granular scour protection around a pile. Just like Van der Hoeven [2002] observed during his research on falling aprons, the stones spread evenly over the front and side slopes of the mound, which form after undermining of the protection has led to the ‘falling’ of the edge stones of the protection. This coverage of stones on the slopes of the mound effectively rearmoured the slopes and prevented further erosion. At the back of the mound this rearmouring is not observed, because the high turbulence levels, introduced by both the mound and the pile, caused stones to become unstable in this area. Furthermore, at the front and side slopes, where the slope of the mound was totally covered by the stones of the protection, the slope angles were constant and comparable to the slope angles that Van der Hoeven found in his research, namely 1:2,0. However, a remarkable difference between the observations of Van der Hoeven and the observations of the current research, concerns the layer thickness of the protection on the slope. Van der Hoeven observed that the layer thickness after launching of the apron was only 1*d f,50 thick, while the current observations show a decreasing layer thickness from the top of the slope to the toe of the mound.

The theoretical approach that is used to develop a design formula focuses on the side slopes, where the flow is parallel to the interface between stones and base material and the varying thickness of the protection on the slope is mainly the result of a varying load along the slope, introduced by the pile. A balance between the volume of the initial protection and the required volume of stones after bed degradation has led to the formulation of the internal slope angle, γ. This angle describes the assumed linearly decreasing thickness along the slope, starting with a certain required thickness at the top, D f,A, to a thickness of only 1*d f,50 at the bottom.

Because the hydraulic load decreases with increasing distance from the pile and the thickness of the initial protection is based on the maximum load near the pile, the assumption that D f,A is equal to the initial thickness of the protection, leads to a conservative design formula. This approach is however taken in the development of the simplified design formula, which results in a linear relation between the bed degradation and the extra extent of the initial protection that should be constructed to deal with that bed degradation.

Student: G. van Velzen Thesis Committee: Prof.dr.ir. W.S.J. Uijttewaal, Ir. H.J. Verhagen, Ir. H. J. Verheij, Ir. B. de Sonneville, Ir. K. Dorst

For further information please contact the section Hydraulic Engineering, 015-2783348 Email: [email protected]

37 | Master’s Theses March 2012

3

Hydraulic Engineering

Pre-Posterior Bayesian Analysis Applied to inspections of hydraulic structures

Existing structures are deteriorating. The deterioration depends on many factors, including workmanship, and therefore it is difficult to predict the exact deteriorating in time. By inspections it is possible to measure the deterioration and create a model with statistics and curve-fitting. Because of the high consequences CF of failure of hydraulic structures, it is important to keep the probability of failure PF low. This follows from the definition of risk:

Risk = PF ×CF Here is

PF

not the true probability of failure, because

this is unknown, but it represents our perception about the probability of failure. The probability of failure consists of aleatoric and epistemic uncertainties about the resistance of and the load on the construction. The epistemic uncertainties can be reduced by inspections, so we will be more certain about the reliability, without changing the structure physically. A low probability of failure for existing structures can be realized by inspections and maintenance. With the inspection results one can determine the condition of the structure and the necessity for maintenance. But what determines the necessity for inspection? This is an interesting question when the inspections are destructive or very costly. When it comes to relatively cheap inspections, this will also play an important role, if they have to be executed a great number of times. Especially if a lot of unnecessary inspections are executed. With the pre-posterior Bayesian analysis one can determine value of certain types and numbers of inspections beforehand. By weighing the value of inspection against the inspection costs, it is possible to develop an optimal inspection strategy.

The method above is applied to the reinforcement bars in a concrete plate of a bridge. The effective diameter of the reinforcement bar is uncertain due to the presence of corrosion. Therefore the strength of the reinforcement bar is uncertain. With the present conditions the risk can be to such a degree, that it is cost efficient to inspect and/or maintain the bridge. The effective diameter can be determined by a destructive and expensive method, of which a number of n can be executed. The total costs exist of the inspections costs and the expected maintenance costs belonging to a number of n inspections. The optimal number of inspections n follows from the minimization of the total costs. Because the inspection results are unknown beforehand, these results are treated as random variables, according to prior knowledge (the deterioration model). Then the cost optimal decision is chosen belonging to a number of inspections n. This is possible because we know that the diameter of the reinforcement bar is uncertain, and that this uncertainty can be reduced by inspections.

Student: S. Al-Baz Thesis Committee: Prof.drs.ir. J.K. Vrijling, Prof.ir. A.C.W.M. Vrouwenvelder, Dr.ir. P.H.A.J.M van Gelder, Ir. A. Willems, Ir. W.D. van der Wiel For further information please contact the section Hydraulic Engineering, 015-2783348 Email: [email protected]

38 | Master’s Theses March 2012

3

Hydraulic Engineering

Baggerpluimen – Ecologische risicoanalyse

Tegenwoordig worden ecologische effecten van baggerpluimen meestal gemanaged op basis van het ‘voorzorgprincipe’. Voorspellingen van concentraties van gesuspendeerd sediment worden gemaakt en vergeleken met grenzen die zijn gesteld door de verantwoordelijke autoriteit. Wanneer men zich niet houdt aan deze grenzen, kan een project vertraging oplopen met extra kosten als gevolg. Het voorzorgprincipe is echter vaag en incorrect, want het neemt de voordelen van een baggerproject niet in beschouwing. De correcte vraag die moet worden gesteld is of een baggeractiviteit mag worden gehinderd door een ecosysteem of dat een ecosysteem mag worden gehinderd door een baggerproject. Om deze vraag te kunnen beantwoorden moet ecologisch risico worden geanalyseerd op een kwantitatieve manier. Een geschikte methode om dit te doen is de Ecologische Risicoanalyse (ERA), die het voor een risicomanager mogelijk maakt onzekerheden expliciet te behandelen. Een ERA bestaat uit de beschrijving van het systeem en zijn componenten, identificatie van gevaren, analyse van effecten, analyse van blootstelling, karakterisering van het risico en een evaluatie die leidt tot feedback voor een mogelijke nieuwe systeembeschrijving. De analyse van effecten relateert de gesuspendeerd sediment concentratie en duur van blootstelling aan het effect bij de gevoelige flora en fauna. Een grafische weergave van deze relatie is een dosis-effect kromme, die de weerstand van een soort weergeeft, ofwel de `sterkte’. Veldwerk of laboratorium experimenten moeten zorgen voor de ontwikkeling van dosis-effect krommen voor belangrijke gevoelige natuur. De analyse van blootstelling begint met de formulering van de baggerpluim bronterm. De complexe dynamische fase van de pluim wordt niet gemodelleerd, maar meegenomen in de bronterm door middel van bepaalde empirische relaties. De passieve fase wordt gemodelleerd door een hydrodynamisch en transportmodel, wat resulteert in een tijdreeks van gesuspendeerd sediment concentraties ter plaatse van gevoelige ora en fauna. Dit wordt vertaald in een concentratie en een duur

van blootstelling, wat kan worden geïnterpreteerd als de `belasting’. Wanneer effecten en blootstelling zijn ingeschat, moet het risico worden gekarakteriseerd. Er zijn verschillende manieren om dit te doen, wat afhangt van de behandeling van de onzekerheden. Een probabilistische analyse neemt variatie in blootstelling- en effectschattingen mee en een deterministische analyse schat _e_en representatieve waarde voor blootstelling en vergelijkt dit met één representatieve dosis-effect relatie. Een probabilistische aanpak maakt het mogelijk een faalkans te bepalen. Dit geeft betrouwbaarheidsintervallen voor de verkregen resultaten en geeft hiaten in kennis aan. Over het algemeen wordt aangenomen dat meer inzicht in kansen leidt tot een betere inschatting van het risico. Wanneer deze methodes in de praktijk worden toegepast, is het afhankelijk van de situatie ter plaatse welke methode het meest geschikt is om het risico in te schatten. In de ontwerp- en planningfase van baggerwerken is een probabilistische analyse te verkiezen om nieuwe gebieden van onderzoek aan te wijzen of de ontwikkeling van een monitorstrategie te ondersteunen. Het is echter duur qua rekenkracht om een Monte Carlo analyse uit te voeren om lange termijn-blootstelling te analyseren. Anderzijds, wanneer baggerwerken inmiddels zijn begonnen, is een deterministische analyse te verkiezen om snel een inschatting van het risico te kunnen maken. Uitvoeringsmethoden kunnen in die fase nog worden aangepast en mitigerende maatregelen kunnen nog steeds worden genomen. Tot slot, voor een kwantitatieve analyse van ecologisch risico is het noodzakelijk een probabilistische analyse uit te voeren. Kosten en baten van een baggerproject kunnen dan worden vastgesteld, wat een complete economische analyse en een transparant besluitvormingsproces mogelijk maakt.

Student: J.H. Becker Thesis Committee: Prof.ir.drs. J.K. Vrijling, Dr.ir. G.J. de Boer, Dr.ir. P.H.A.J.M. van Gelder, Ir. C. den Heijer, Dr.ir. Z.B. Wang, Prof. C.F. Leung, Associate professor V.M. Babovic, Dr.ir. M. van Koningsveld For further information please contact the section Hydraulic Engineering, 015-2783348 Email: [email protected]

39 | Master’s Theses March 2012

3

Hydraulic Engineering

The floating construction method

Parking problems in cities become more significant every day. Parking tariffs are going through the roof and parking spaces are limited. Therefore, cities are researching alternatives for parking on ground level and underground. One of these alternatives is parking underwater.

Amsterdam

The parking garage

One of these cities is Amsterdam. This city ranks number 5 on the list of most expensive cities to park in Europe. To create more parking spaces, the city of Amsterdam is researching the possibility of parking garages underwater at several locations. One of these locations is the Oosterdok near the central train station. A feasibility in 2009 study showed that a parking garage underwater with 350 parking spaces and constructed with the traditional construction method is not financially feasible. [Oosterdok, 2009]

The floating construction method This situation is used to determine whether or not a new construction method could be the solution, namely the floating construction method. With this construction method, the structure is constructed directly on the water. The base consist out of a floor of EPS and concrete. This floor floats and makes it possible to construct the rest of the structure on top. This process is shown in the figure below. The advantage is the fact that an expensive temporary construction pit isn’t needed, which normally forms 20 to 30% of the total construction costs!

Flexbase floor The floating floor consist of the patented Flexbase system and is shown in the figure below. It starts with constructing a 800mm thick EPS floor consisting of 4 layers of glass fibre reinforced EPS250. Directly on top of this EPS floor the concrete floor is poured. When this floor is hardened the formwork, consisting of EPS60 blocks, for the beam grid is placed. When the beam grid is poured and hardened, the second and last floor is constructed to end up with a floating sandwich structure.

The parking garage is constructed directly on top of the Flexbase floor. The parking garage has two floors and 750 parking spaces. It is 129 meters long, 76 meters wide and 6,5 meters high. This does not include the 2,05 meter thick Flexbase floor. When the garage is finished, it still floats and has a draught of 6,05 meters.

Immersing the parking garage When the garage element is completed, it is immersed. Ballast tanks are placed inside the element and filled with water. When the element is at the desired depth and level, grout anchors are drilled through the floor to keep the element immersed. The ballast tanks are emptied and the garage element is coupled to the entrances for cars and pedestrians. The entrances are constructed separately.

Conclusions The floating construction method is technically and financially feasible for this situation. The floating construction method is approximately 11,5% cheaper than the traditional construction method. When the benefits come exclusively from parking fees, the floating construction method becomes financially feasible for this situation with hourly parking tariffs of €2,16. This research shows that the floating construction method could be a better and cheaper alternative for traditional construction methods.

Student: R. Hendriksen Thesis Committee: Prof.drs.ir. J.K. Vrijling, Ir. W.F. Molenaar, Ir. W.J.M Peperkamp, Ing. W.J. Schilder

For further information please contact the section Hydraulic Engineering, 015-2783348 Email: [email protected]

40 | Master’s Theses March 2012

3

Hydraulic Engineering

The feasibility of a commercial osmotic power plant

Osmotic power is a form of renewable energy which is currently not used at a commercial scale, but it might have the potential to be exploited in a sustainable manner in the near future. It uses the principle of osmosis, which is known for over a century and is used since recent years for several membrane applications. The salinity gradient between fresh river water and salt sea water, separated by a membrane, causes an osmotic flow which can be converted into electricity by using one of the two types of osmotic power generation, PRO or RED. Interested parties have already concluded, by conducting laboratory studies and operating pilot plants, that osmotic power is a promising source of renewable energy in the future. An energy unit rate of 8 cents/kWh should be possible for a commercial-scaled power plant. However, what is lacking in these studies is the actual design of the osmotic power plant. Scaling up of an osmotic power plant to a commercial scale will have a major impact on the design of the main infrastructure. The question is whether a commercial osmotic power plant is feasible if the capital costs of the main infrastructure are included. Answering this question is the objective of this thesis.

The research question is answered by conducting multiple case studies with a varying capacity. By considering the revenues and investments over the lifespan of the power plant, the energy unit rate of each power plant is obtained. The general conclusion is that, with the present technology and knowledge, the energy unit rate deviates too much from a marketable energy unit rate. The high capital costs of the intake and outfall system and pre-treatment facility, and the low power plant efficiency ensure that a commercial osmotic power plant is not economically justified. The commercial exploitation of an osmotic power plant is therefore far from being feasible. However, when a number of expected and recommended developments are considered, the energy unit rate will approach a marketable value. The commercial exploitation of an osmotic power plant could therefore be feasible in the near future. Though, the occurrence of these recommended developments seems to be an utopia. The answer to the research question is therefore that the future commercial exploitation of osmotic power is not feasible.

Student: R. Kleiterp Thesis Committee: Prof.drs.ir. J.K. Vrijling, Ir. W.F. Molenaar, Dr.ir. J.H.G. Vreeburg,

For further information please contact the section Hydraulic Engineering, 015-2783348 Email: [email protected]

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Hydraulic Engineering

Differences between a 3 dimensional probabilistic and the traditional method of berthing structure design

Jetties are designed by the guidance of the deterministic standards. These standards are based on the standardized values of safety factors (semi-probabilistic) and use the load and the capacity of every element as a standard value. The interaction of every separate element as a part of a whole is not taken in to account. The use of deterministic standards can result in a design that is not economically optimal. A probabilistic approach gives a better insight in the occurrence of an unwanted events and leads to more insight of the optimizing of the structure. The “Lyondell jetty” in the Europort in Rotterdam is used as reference structure. This jetty is constructed in 1997 and is in use by a manufacturer of chemical derivatives for all kinds of synthetic products. It concerns a continues berthing structure founded on piles and is covered with fender wood, with a double deck jetty, that offers space to berth two large sea vessel and two smaller barges. The failure of the berthing structure is a conditional chance for functioning of the jetty. The berthing structure is submitted to further examination by means of a Monte Carlo simulation. Using the Monte Carlo simulation a measure of failure of an event is expressed in strength and resistance. In this study this event consists of reaching the yielding stress in the structure or the exceeding of a determined boundary of deformation during the berthing of a vessel. The energy loading is introduced with the equation of Saurin. The soil is modelled as a spring and meets the requirements of the Winkler model. In analysing the deformations of the structure the soil needs to have elasto-plastic characteristics (p-y curves that were developed by Reese).

In this thesis only the berthing of the mooring point 2 (large sea vessel) is considered. First the question if the developed 3 dimensional simulation technique is applicable answered and second whether the application of the model leads to differences in capacity. The soil model developed in Scia-engineer has the same behavior as in M-pile and the structure shows the expected behavior according the rules of mechanics. In the model relating to the energy load the variables of length, width, depth, mass, angle of berthing and the coordinates of impact are described as a stochastic. In the resistance of the structure the volume weight, internal angle of friction, cohesion, yielding stress and wall thickness of the tubular segments are described as a stochastic. From the results it appears that the loads occurs only very locally. Consequently there appears an over capacity in the reference design relating to the length of all the piles and the diameter of the piles. The five most loaded piles in the structure are checked due to the energy loading of the bow at Mooring Point 2. It appeared that the diameter of these piles can have a smaller fitted diameter. In length a reduction of 9% is found. A trend can be distinguished that indicates a large reduction of capacity in length over the whole structure. The critical variable in the design is the velocity of the vessel. The critical element in the structure is the berthing beam self. The sensitivity analysis of strength indicates that the chance of failure in strength can be diminished by the strengthening of the berthing beam and reducing the thickest wall thickness’s of the piles.

The actual structure that was designed with the Blum method, the design was recalculated, using help of p-y curves. This becomes the Kool model that is used for comparison with the results of the Monte Carlo simulation.

Student: J. Kool Thesis Committee: Prof.drs.ir. J.K. Vrijling, Prof.ir. A.Q.C. van der Horst, Dr.ir. J.G. de Gijt, Dr.ir. P.H.A.J.M. van Gelder, Ir. L. Groenewegen, Ir. D. Dudok van Heel For further information please contact the section Hydraulic Engineering, 015-2783348 Email: [email protected]

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3

Hydraulic Engineering

Risk to life due to Flooding in post-Katrina New Orleans

After the catastrophic flooding of New Orleans due to hurricane Katrina in the year 2005, the city’s hurricane protection system has been improved to provide protection against storms with at least a 100 year return period. This thesis investigates the risk to life in the post-Katrina situation for the New Orleans metro bowl. The risk to life is evaluated through a ‘scenario’ based approach simulating defined flood events.

Finally, the effect of various risk reduction measures on the risk level is investigated. Strategies for which costs and risk reduction effects are discussed, including: elevated homes, improved evacuation and increased protection (relocation of population to higher areas). While decisions regarding flood risk are complex and involve many factors such as perception and economic considerations, the results indicate the necessity of further discussion regarding the management and reduction of the city’s risk to flooding.

Several scenarios are identified that could lead to flooding within the Metro Bowl and including the failure of hurricane protection or the river levees. The probability for each scenario is determined based on existing design guidelines and expert judgment. A two-dimensional hydrodynamic model is used to simulate flood characteristics and these outcomes are used as input for the loss of life estimate. In addition, the evacuation effectiveness has been considered. Results indicate that the estimated loss of life in case of flooding ranges from about 100 to nearly 500. The highest life loss value is found for breaching of the river levees. The probability and consequence estimates are combined to evaluate the individual risk and societal risk for New Orleans. The individual risk (IR) refers the probability of an individual residing in a given area perishing as a consequence of flooding. The IR for large parts of New Orleans metro is larger than 1/100,000 per year. The evaluated risk is compared to risk levels that have been found to the risks of other large scale engineering systems (e.g. other flood prone areas in the US and other regions, dams and the nuclear sector) as well as existing criteria for evaluating acceptable levels of individual and societal risk. The evaluated risk determined in this study exceeds tolerable or acceptable risk criterion as discussed in literature and other industries. Despite the major improvements to the flood protection system, the societal flood risk of New Orleans is still expected to be significant at a national (US) scale.

Student: A.L. Miller Thesis Committee: Prof.drs.ir. J.K. Vrijling, dr.ir. O.A.C. Hoes, dr.ir. S.N. Jonkman, dr.ir. M. van Ledden

For further information please contact the section Hydraulic Engineering, 015-2783348 Email: [email protected]

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Hydraulic Engineering

Rip Current Characteristics at the Dutch Coast At the example of Egmond aan Zee

Background Rip currents are narrow, seaward directed flows in the surf zone that can pose a serious threat to swimmers. This issue has received attention particularly on swell dominated coasts (such as the US, Australia, France and UK) where numerous field experiments have been undertaken. However, the threat of rip currents is less recognised on wind-sea dominated coasts such as the North Sea, even though a consistent number of swimmers drift offshore (in rip currents) and require rescue by surf lifeguards each year (for example at Egmond aan Zee, The Netherlands).

Field experiment In August 2011, a five day field experiment was conducted at Egmond aan Zee. Lagrangian velocities in the surf zone were measured with drifter instruments and human drifters that were tracked via GPS. An extensive dataset of measurements was collected from which parameters that govern the strength of rip currents and affect their mean flow properties were identified. Three flow patterns were observed in the experiment: (1) a locally governed circulation cell, (2) a pattern in which the drifter initially floats offshore and then is advected by a strong long-shore current and (3) a meandering longshore current. A variety of rip current velocities were measured with the strongest being approximately 0.6 m/s. A statistically significant correlation between the ratio of offshore wave height over water depth on the bar and rip current speeds was established from the data.

eters tested were channel width and depth. A reduction of the hydrodynamic parameters along with simplification of the model bathymetry allowed for identification of the governing rip current parameters. Sensitivity of Rip currents to Hydrodynamic and Geometric Parameters The sensitivity analysis demonstrated that rip currents strengthen with increasing wave height, decreasing water depth over the updrift bar and increasing channel depth. The influence of the wave period was of secondary importance and the wave angle did not affect the offshore rip current velocity for site specific channel dimensions. The wave angle was observed to only have an impact for relatively narrow channels (relative to the forcing).

Particularities of Rip Currents at the Dutch Coast This study revealed similarities and differences of rip currents at the Dutch coast and rip currents at previous field sites. The driving parameters of rip currents were identical; however, the flow patterns differed. While in previous field experiments drifters were predominantly retained within the surf zone, most drifters at Egmond aan Zee were ejected from the surf zone and did not return shoreward. Offshore of the channel the drifter behaviour was governed by the tidal current that advected the drifters alongshore. In case of weak tidal currents (slack water) the rip currents extended far offshore.

Numerical Modelling of Rip Currents A 2-dimensional hydrostatic XBeach model was validated against laboratory rip current experiments and field data from Egmond aan Zee. A sensitivity analysis was performed to test a range of hydrodynamic and geometric parameters. Various hydrodynamic scenarios of wave height, wave period, wave angle and tidal water level were tested to evaluate the influence on rip current initiation and mean flow properties. Additionally, the importance of wave and tidal driven longshore currents was investigated. The key geometric param-

The picture shows GPS tracked drifters floating offshore in a rip current at Egmond aan Zee. The photo was taken by Prof.dr.ir. Dano Roelvink.

Student: G. Winter Thesis Committee: Prof.dr.ir. M.J.F. Stive, Dr.ir. J.S.M. van Thiel de Vries, Ir. M.A. de Schipper, Ir. R. Morelissen, Dr.ir. M. Zijlema For further information please contact the section Hydraulic Engineering, 015-2783348 Email: [email protected]

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Hydraulic Engineering

Port of Rotterdam Anchorages Study An occupancy evaluation using Simulation

The Dutch part of the North Sea is one of the most intensively used seas worldwide with some 110.000 shipping movements per year. Apart from international shipping routes that run along the Dutch coast it contains busy shipping routes to and from the ports of Rotterdam, Antwerp, Zeebrugge, Amsterdam and Eemshaven/Delfzijl. Besides shipping, it has many other functions, such as oil and gas extraction, production of wind energy, fishing, etc. All these functions take space and hence spatial planning at sea involves lots of stakeholders with different and often conflicting interests. Anchorages are required for smooth and safe shipping and hence efficient port operations and are therefore an indispensible part of port logistics and infrastructure. The Port of Rotterdam Authority, however, can only partially substantiate the claim of space for anchorages in the North Sea, introducing a risk of anchorages being neglected in planning policy on the North Sea, while due to increased shipping there may be a need for more (space for) anchorages. Anchorages are used by vessels to wait for orders, available mooring, tidal window, do repairs, etc. Within an anchorage, a captain is free to choose its anchoring position and drop its anchor on that location. The most important aspect of the anchoring manoeuvre is that the vessel has to be able to anchor heading into the resultant of wind and current. Once anchored, the vessel ´occupies´ a circle in the anchorage with its anchor as midpoint, as it has to be able to swing around its anchor unhindered if wind and current change direction. The radius of this circle depends on the water depth in the anchorage, the length of the vessel and a safety margin, to allow for some anchor drag. In the offshore approach of the port of Rotterdam there are currently 9 anchorages in use. The Port of Rotterdam Authority does not assign vessels to a certain anchorage, but merely gives recommendations, as a captain is free to anchor wherever he likes. Specific anchorages are mostly recommended based on origin and draught of the vessel. The anchorages in the offshore approaches of the port of Rotterdam were visited by 8130 vessels in 2010,

containing various types of vessels, each with its own characteristic distribution of length, draught, origin, inter arrival time and dwell time, of which the average dwell time seems to depend on external economic indicators. The occupancy within these anchorages at present is low, with a maximum instantaneous occupancy of 44.7% of the anchorage located nearest to the port entrance in 2010. This suggests there is ample space available for more vessels to anchor, however, the capacity of an anchorage is not 100%, but rather a range of occupancies depending on the mix of arriving vessels, anchorage configuration (size and shape) and the vessels already anchored in the anchorage. As the rejection of vessels occurs at high occupancies, the capacity of the anchorage needs to be sufficient to deal with peaks in occupancy.

Using historical data of anchoring vessels a simulation model is constructed that correctly and accurately simulates the anchoring of vessels and the corresponding decisions made by captains in choosing a specific anchorage and an anchoring position within the anchorage. The simulation model is versatile and can be used as a decision support tool for the Port of Rotterdam Authority, to e.g. assess and compare different configurations of the anchorages, anchorage assignment rules and anchoring algorithms can be tested. With the simulation model the occupancies of the anchorages for two future scenarios were evaluated. Although increases up to 109.7% were seen (72% on average), the absolute occupancy levels remain acceptable, indicating that no anchorage capacity problem is expected in the near future. If capacity shortage is expected though, the testing of two anchoring capacity improving algorithms with the simulation model shows that the capacity can be improved op to 14.3% when the WALLPACK algorithm is used for allocating anchoring positions to incoming vessels. Implementation of this in practice would require legislation and policy changes.

Student: S.B. Devillé Thesis Committee: Prof.ir. T. Vellinga, Dr.ir. W. Daamen, Ir. M. De Jong, J.W. Verkiel.

For further information please contact the section Hydraulic Engineering, 015-2783348 Email: [email protected]

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Hydraulic Engineering

Sedimentation in the Botlek Harbour A research into driving water exchange mechanisms.

Problem Siltation of harbour basins and navigation channels is a serious problem in the port of Rotterdam as well in many other harbours all over the world. Due to siltation, basins and channels require frequent maintenance dredging to guarantee safe navigational depths. The costs associated with these dredging activities are quite high.

Costs To keep the channels and harbours in Rotterdam navigable, Rijkswaterstaat and the Port of Rotterdam are dredging approximately 15 million m 3 of sediment a year. The dredging cost of the Botlek Harbour only is already about 3 million Euros a year. It is a task to keep the costs in the Port of Rotterdam as low as possible to compete with other ports. Reducing maintenance dredging costs is in line with the goal of the Port of Rotterdam to be the most competitive, innovative and sustainable port in the world. Most sedimentation within the maintenance area of the Port of Rotterdam occurs in the Botlek. According data, between 1.5 and 3 million m 3/year is dredged in the Botlek Harbour. Although the current dredging philosophy more or less works, the question arises whether there are solutions that are more cost-effective. However, the problem is so complex that it narrowed down for the sake of research quality.

Research and results The main causes of siltation in general and specifically in the Botlek Area form an important part of the study. Hydrodymical models (SIMONA & Delft3D), were used to gain insight in the sedimentation problem. The focus in this thesis was more on the hydrodynamics. The exchange mechanisms between the river and Botlek Harbour were investigated, which were needed to examine the effectiveness of certain solutions. In practice a lot of solutions are proposed in literature, however in this study only a couple of ‘hard’ measures are investigated. The first possible solution that was examined was the use of a Current Deflecting Wall. It turned out that the hydrodynamics were very sensitive

to the configuration of the CDW. While sometimes it would lower the exchange flow, at other cases it would even make the problem worse. The second solution was to make a gap in the Geulhaven dam. However this was not a good solution as high exchange flows occurred. The last proposed solution, the filling of the underwater dam, seemed more feasible as it would decrease the exchange flow according the numerical models. The research has first order results which can be used in further studies. According to this results, certain solutions will decrease the exchange flows. On turn it would very likely result in lower sedimentation rates in the Botlek Area. It is expected that some CDW configurations and the filling of the underwater dam would have a positive effect when it comes to sedimentation. However, this research is the first step of an extensive study that must made to deal with the problem.

Recommendations First of all many things can be done to improve the models, for example by using a higher spatial resolution. Secondly, other sets of conditions must be modelled to see what kind of effect this has on exchange flows. In addition, sediment must be included in the models to have more insight on the sedimentation itself. The next step would be a feasibility study, including a cost benefit analysis. It would be wise to improve the models further and to make a scale model for the most feasible solution. In the ideal case, were all steps are positive and hard conclusion can be made, it would be a good idea for the Port of Rotterdam to start a pilot.

Student: A. El Hamdi Thesis Committee: Prof.ir. T. Vellinga, A. Noordijk, Prof.dr.ir. H. Winterwerp, P. Taneja, Prof. Cheong Hin Fatt, Dr. M. Chui Ting Fong For further information please contact the section Hydraulic Engineering, 015-2783348 Email: [email protected]

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Hydraulic Engineering

Coal transport Kalimantan

This master thesis focuses on the transportation of coal from two coalmines in South Kalimantan to the Java sea. Coal has to be transported from the coal mine area, situated hundred kilometre land inward, to a location with sufficient water depth, at the mouth of the river Barito. The objective of this master thesis is summarized in two research questions. What are the possibilities to transport coal from the mine hundred kilometre land inward to a location with sufficient water depth to load Cape-size coal carriers? Which of the alternatives are most feasible from a technical and financial point of view?

The current transport system consists of several cycles of barges, where full barges sail one way and empty barges sail the other way back. Two different cycles have been investigated. A cycle with barge transport between two terminals and a cycle with barge transport between a terminal and an anchorage for loading coal carriers. Hydraulic transportation of coal is an unconventional transport mode. Hydraulic transportation of coal is very similar with the transportation of sand in the dredging industry. The coarse coal is first mixed with water and then transported through a pipeline by means of a number of centrifugal pumps in series. The main differences between a coal-water slurry and a sand-water slurry are the density of the particles and the average particle size (dm 50). Sands consists mainly of quarts with a density of 2650 kg/m 3, while coal has a density between 1100 kg/ m 3 and 1500 kg/m 3, depending on the quality and the origin of the coal. The particles are transported in water, therefor the relative density underwater determines the tendency of settling. The relative density is 1650 kg/m 3 for sand, respectively 300 kg/m 3 for coal particles. This means that the tendency of settling is around 5 times higher for sand than for coal.

The biggest challenge for the new transport system is to increase the throughput capacity five times in five years. Three different transport modes have been investigated in this thesis. Those are; transport by barges, conveyor belt transport and hydraulic transport. A comprehensive logistics study is performed with the use of a simulation model. The simulation model is written in Matlab and is a so-called event based model. The transport configuration which is lowest in transport costs, is determined with the results from the simulation model. A transport configuration is a combination of the number of barges, number of berths and the loading capacity of the berths.

The particle size of coal, when it is exported, is much larger than the average particle size of sand (between 63µm 2000µm). Larger particle sizes will increase the turbulent behaviour of the slurry. Different formulas for a coal-water slurry are analysed. In the analysis is investigated which influence the particle density and particle size have on the friction head in a particular formula.

Student: B.C. Joppe Thesis Committee: Prof.ir. T.Vellinga, Ir. P.Quist, Dr.ir. W.Daamen, Ing. M.G.M.Huijsmans

For further information please contact the section Hydraulic Engineering, 015-2783348 Email: [email protected]

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Hydraulic Engineering

Analyzing the hydraulic design for the new basin in the IJmuiden outer harbor

To improve the lightering conditions of bulk carriers in the outer harbor of IJmuiden, the lightering facility will be transfered to a new harbor basin that will be implemented at the location of the dredging depot in the former Averij harbor. The Dutch Directorate-General for Public Works and Water Management (RWS) demands that down time of the lightering operations inside the new basin does not exceed 5% of the operating time of 365 days a year, 24 hours a day. Down time of the lightering operation can be caused by several issues. This thesis investigates the contribution of long waves with wave periods between 10 and 250 seconds to the down time conditions. Theoretically this long wave climate can cause high ship response as incoming wave periods are close to the bulk carrier’s natural periods. The long waves can also cause resonance in the new basin or in the outer harbor as a whole. A coupled system of basin resonance and ship response is also investigated as the two separate resonance systems can enforce each other for certain wave periods.

island. Especially in the Hoogoven harbor and at the Noorder ship lock wave agitation decreases. However, standing waves may arise between the new basin and the opposing IJmond harbor if sufficient wave energy is present in the incoming wave climate. The results of the coupled system of basin resonance and bulk carrier vertical response do not result in a contribution to the down time criteria. Although amplified waves can become a factor 4.5 larger than the incoming wave heights, earlier investigation and observations and analyses in this study show that the incoming wave energy for long waves is low and the probability of incoming waves amplifying into waves of critical wave heights that cause down time to the lightering process is very little. The contribution to the down time of the new basin is very small in comparison to the contribution of wind and locally generated wind waves.

Investigating a 200.000 DWT bulk carrier’s Response Amplitude Operators for an open water situation concludes that the bulk carrier experiences enforced movement in its horizontal motions for wave periods around 250 seconds and in its vertical motions for wave periods between 15 and 20 seconds. In the real time situation the ship’s horizontal motions will be damped by the mooring system and the high resonance periods will not be met. The numerical wave model PHAROS has been used to analyze whether resonance patterns arise in the outer harbor basins for a wave period band between 10 and 250 seconds. It is concluded that the new basin can experience resonance for wave periods between 100 and 250 seconds. The highest wave amplification of 4.5 times the incoming wave height at sea occurs for an incoming wave period of 147 seconds. The amplified wave height inside the new basin will not contribute to down time conditions as the amplified wave height is lower than the critical wave height of 0.80 meter. The implementation of the new basin has a positive ffect on the area of the outer harbor behind the Fort

Student: P. Kaufmann Thesis Committee: Prof.ir. T. Vellinga, Dr.ir. R.J. Labeur, Ir. M. de Jong, Ir. B. Wijdeven

For further information please contact the section Hydraulic Engineering, 015-2783348 Email: [email protected]

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Hydraulic Engineering

Pump jets in inland vessels Use and effect on bed material

The traffic intensity at the Amsterdam-Rijnkanaal has not grown

is based on the free propeller theory. In the case of a pump jet,

in the past decade. However, the maximum transported tonnage

part of the contraction takes place inside the unit. Furthermore,

has increased substantially. Thus, the average loading capacity

the flow field has been subdivided in three parts: initial outflow

of ships has been increased. In other words, bigger ships have

velocity, axial flow velocity and the flow velocity distribution in

been replacing the small ships. A direct consequence is the use

the region of the established flow. The coefficients in the model

of larger main propellers and increased installed engine power

have been empirically determined using a simulation with a CFD

in order to realize acceptable ship speeds. To improve the

model. The non-linear least-squares method has been applied.

maneuverability, the power of auxiliary bow and stern propul-

This model has been compared to flow fields induced by different

sion systems has increased as well. This results in higher flow

other propulsion systems. It results in a similar axial flow velocity

velocities and thus more damage to bed protections at berthing

decrease as a low-powered water jet. However, the pump jet

places. Especially pump jet thrusters as a bow propulsion system

diverges faster and with a greater angle than any other jet.

may attack the bed protections more severely due to a vertical component of the flow field induced by the pump jet which is

The derived model has been used to investigate the stone

directed towards the bed.

stability at the toe of a sheet pile wall. Firstly, the flow velocities at the bed have been evaluated by looking at berthed ships in

The Dutch Department of Waterways and Public Works has

different conditions (fully loaded, partly loaded and unloaded).

detected scour holes at berthing places at the Amsterdam-Rijn-

Secondly, a stability analysis of the bed material has been

kanaal. The question has arisen whether pump jets are respon-

executed by using a method presented by Deltares. However, in

sible for the scour holes. Therefore, the aim of this research is

order to protect the bed against the high flow velocities, large

to develop an analytical model for the flow field induced by the

stone diameters are required.

pump jet thruster. Subsequently, the required dimensions of a

An alternative is allowing scour holes to occur, but the length of

bed protection has been determined as well as an investigation

the sheet piling should be extended in order to maintain stability

on the possible scour effects in case of an unprotected bed of the

of the entire quay wall. The predicted maximum scour depths

Amsterdam-Rijnkanaal.

(by using a time independent method) caused by a pump jet are in the same range of measured scour depths at the Amsterdam-

In order to meet this goal, an inventory of the bow propul-

Rijnkanaal. This means that scour holes may cause instability

sion systems in inland vessels has been made by conducting an

problems of the existing sheet pile walls.

inquiry. Subsequently, the different propulsion systems have been compared qualitatively. Since existing formulas are based on the circular free jet, this system is also treated in the comparison. In addition, a water jet (hydro jets can be distinguished in low-powered and high-powered jets), often used as propulsion system by ferries, has been taken into account due to the strong analogy with the circular free jet. As a result, both the ratio of decrease of axial velocities and diffusion of the jets in radial direction of a circular free jet strongly correspond to a highpowered water jet. However, the free propeller and transverse tunnel thrusters are considered to have a faster decrease of axial velocities and a faster diffusion of the flow field. The applied power and the induced turbulence seem to be the main reasons for the flow field characteristics. An essential part of this research is the derivation of an analytical model for the pump jet thruster induced flow field. The principle

Student: J.R.C. Manaois Thesis Committee: Prof.ir. T. Vellinga; Ir. H.J. Verheij; Dr.ir. H.J. de Koning Gans

For further information please contact the section Hydraulic Engineering, 015-2783348 Email: [email protected]

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Hydraulic Engineering

Optimizing the passage of fast ferry navigation at the Schellingwoude lock complex

Traditionally, water based public transport has a large contribution to the accessibility of rural areas in the Netherlands. Initiated by the industrial revolution a major shift from water based to land based public transport occurred. Until recent history water based public transport was considered unfeasible. Nowadays land based transport modes are threatened by their own success. The shortage of land available for land based public transport in rural areas creates congestion on highways and endangers the accessibility of many city centres. City centres which adopted their metropolitan status due to their location near the waterfront. This fact gives rise to investigate the feasibility of water based public transport in existing city centres and areas to be developed. The expansion of Almere, being part of the Amsterdam metropolitan region, outside the existing flood defence system in lake Markermeer is a strong example showing a large potential on accessibility by means of fast ferry navigation. An integral planning of water and land based infrastructure serving commuter related passenger transport, among other success factors, increases the success of tackling bottlenecks in the existing hydraulic infrastructure. For the water based public transport connection between Amsterdam Central Station and Almere the passage of the Schellingwoude lock complex is considered to be the most significant bottleneck causing previous attempts of shipping companies on this route to fail due to a lack of feasibility. Contradictory functional demands present at this lock complex in combination with the large yearly volume of commercial and recreational navigation passing this lock complex during the normative month (August) causes the lock operation process to involve an average passage time of fast ferry navigation outside the target conditions associated with water based public transport. In order to optimize the passage of fast ferry navigation at the Schellingwoude lock complex the feasibility of multiple lock system alternatives is investigated, being: • • Alternative 1a – Priority arrangement; • • Alternative 1b – Priority arrangement and separate locking method; • • Alternative 2a – Reservation of one lock chamber; • • Alternative 2b – Reservation of two lock chambers;

• • Alternative 3 – Priority arrangement and reservation of one lock chamber; • • Alternative 4a – Additional minimal lock chamber; • • Alternative 4b – Additional CEMT-class Vlb lock chamber; • • Alternative 5 – Additional innovative structure. The performance criteria determining the feasibility of the proposed lock system alternatives are based on the target conditions associated with water based public transport derived from a travel time analysis on the preferred route between Amsterdam Central Station and Almere. The actual performance analysis is elaborated using the SIVAK2 simulation model. From the performance analysis it is concluded that reservation of one lock chamber (Alternative 2a) and the construction of an additional lock chamber with minimal dimensions serving fast ferry navigation (Alternative 4a) are the best performing alternatives. Both alternatives lead to an average passage time of fast ferry navigation within the target conditions associated with fast ferry navigation and within the prescribed target conditions applied for commercial and recreational navigation. The best performing alternatives are further investigated using a social cost-benefit analysis. This analysis shows that alternative 4a involves the least costs associated with direct effects compared to alternative 2a during a life span of 100 years. This is mainly due to the effect of large financial consequences of additional waiting time of commercial and recreational navigation passing the Schellingwoude lock complex.

Student: M.J. Rispens Thesis Committee: Prof.ir. T. Vellinga, Ir. M. Wolters, Dr.ir. W. Daamen, Ir. H. van Hees

For further information please contact the section Hydraulic Engineering, 015-2783348 Email: [email protected]

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Hydraulic Engineering

Flexible Port Infrastructure on Maasvlakte 2

Port of Rotterdam Authority decided to construct Maasvlakte 2 to cope with demand for port areas. Maasvlakte 2 is a business case driven project. The outcome of the business case has led to the construction of an entire sea defense and the realization of port areas in phases, in response to client demand. The phased development results in the creation of a temporary inner lake. The temporary use of this inner lake by port activities is hampered by the large investments generally required for port infrastructure. This research examines the possibility of allocating temporary activities to the temporary inner lake of Maasvlakte 2, using flexible port infrastructures. Potential activities are inventoried and ranked in a brainstorming session. Potential structures are investigated through a literature study. Activities are coupled with structures to create alternatives. These are allocated on the inner lake, depending on their functional requirements. The common barge terminal is the only activity that requires a quay type structure. The objective of this research is to examine the financial viability of an activity using a flexible structure. The common barge terminal concept is examined in detail. A common barge terminal is a neutral transshipment point that enables inland vessels to transship their containers at one inland quay instead of at several deep sea quays. Its results in a win, win, win situation: Inland vessels operators do not have to hop from one terminal to the next. They sail shorter distances and can reduce their turnaround time in the Port of Rotterdam. Container terminal operators have more time and space to handle sea going vessels. Sea going vessels are served by more cranes and can transship more containers per time per quay length. The additional quay capacity enables to postpone expansions. Port of Rotterdam Authority can postpone deep sea quay expansions. The latter is examined in detail. Port of Rotterdam Authority can postpone several deep sea quay expansions. There are three container terminal operators on Maasvlakte 2 that want to expand in several phases. Postponing deep sea quay expansions saves investment costs and leads to a loss in rent. The future value of

costs and revenues are lower than the present value. A discount factor reduces future to present values. The net present cost savings cumulates the discounted cost savings and losses in rent of all postponed expansions. The net present cost savings for Port of Rotterdam Authority are larger than 15 M€, if the: inland vessels that call with 50 TEU or less are handled at the common barge terminal, discount rate is at least 8.5%, percentage transshipped in call sizes <50 TEU is at least 4.2% of the total throughput and the increase in container throughput is at most 6% OR the small call size percentage is at least 2.1% and the throughput increase is at most 3%. Port of Rotterdam Authority not only saves cost with a common barge terminal, but also has to invest in a quay and receives rent from the common barge terminal operator. Several structures are compared by their whole lifecycle costs. Containerland consists of several containers sandwiched between two concrete slabs and has the lowest whole lifecycle costs. The service life of the inner lake is considerably shorter than the technical lifetime of the structures. Structures can be reused, sold or demolished. Reuse-possibilities have to be considered in case the rest value after the service life of the inner lake is large. Port of Rotterdam Authority can generate 3 M€ rest value in case the service life is 10 years and the discount rate 8.5%. The rest value is 5 M€ in case the service life is 5 instead of 10 years and 7 M€ in case a discount rate of 4.5% is used instead of 8.5%. Reusepossibilities have to be considered in case the discount rate is low (4.5 instead of 8.5%) or the service life is small (5 instead of 10 years).

Student: R. Ros Thesis Committee: Prof.ir. T. Vellinga, Ir. P. Taneja, Dr.ir. J.G. de Gijt, Dr.ir. R.J. Verhaeghe, Ir. M. van Schuylenburg For further information please contact the section Hydraulic Engineering, 015-2783348 Email: [email protected]

51 | Master’s Theses March 2012

Development Plan Dordrecht Seaports Determination of the potential segments for the Dordrecht Seaports

Dordrecht Seaports (DS) is a port with a direct connection to the North Sea. In the current situation not all companies are port related. The port related companies are active in the storage of liquid bulk and dry bulk with especially ore & scrap. The yearly throughput of the DS is 3,2 million tons in 2010. After an analysis it can be concluded that this port at the moment is not used as a sea port, but as an inland port. With an analysis is shown which segments can optimize the port. This analysis is done from three different analysis pillars. In the first pillar (area) is concluded that the DS is surrounded with other business areas in the surroundings. For adding values to the cargo, new business areas can be used. Besides that, the DS can contribute as an added value in the (port) network of Rotterdam. With enlargement of DS in the network of PoR, PoR can also contribute on advantages. The second pillar is the pillar of stakeholders. Next to the PoR, also the municipality of Dordrecht, the companies within the DS and the Drechtsteden are the most important stakeholders. Their main issues are accessibility and the economic progress. The last pillar of analysis is the vision of PoR. From the Havenvisie 2030 the growth percentages of each segment are the base for the determination of the growth percentages of the DS. With a band width between two scenarios, a translation of the growth percentages is determined. The expected growth of the throughput of the DS in 2022 is between 3,5 and 3,9 million ton per year with a large increase for the segments coals and ore & scrap.

Per pillar the potential segments are determined. Maritime industry and other general cargo have a high potential, which is in contrast with the short sea and Ro/Ro. The ideal situation is sketched. It is concluded with these segments classification in the basins in combination with extra implementations to optimize the port, a new throughput is expected between 6,5 and 6,9 million ton for 2022. With a case study of damping a basin it is shown that more throughput can be realized. With some minor changes in the variables of the incomes, this will be profitable. This means that PoR has realistic options to optimize DS.

Student: M.J. Verhage Thesis Committee: Prof.ir. T. Vellinga, Drs. M. Oosting, Ir. P. Quist, Prof.dr. R. Zuidwijk

For further information please contact the section Hydraulic Engineering, 015-2783348 Email: [email protected]

52 | Master’s Theses March 2012

4. Civil Engineering theses

Geo-Engineering

4

Geo Engineering

Time dependent processes on passive loaded piles

The effect of time-dependent processes on passive loaded piles is investigated by means of the finite element program PLAXIS 3D and measurement data from a full scale test. The full scale test is part of an investigation program called GeoImpuls, and consists of a sand embankment of 3 m height on a 3,6 m thick peat layer. The dimensions of the full scale test and the model in PLAXIS are equal. The measurement data from the full scale test are processed into graphs which show the development of the horizontal soil deformation in time at four locations. The piles installed in the full scale test consist of two HEA300 steel profiles, and were installed after construction of the embankment. A square hollow section tube is welded onto the HEA300 in which an inclination measurement can be performed. In order to perform a better determination of the bending moments, the measurement interval of the inclination measurement has been reduced from the regular 0,5 m to 0,1 m. In processing the results a biasshift has been recognized for which a correction has been applied. The maximum measured displacement of the piles was a few millimetres.

At the site of the full scale test an extensive soil investigation program has been carried out. Soil parameters have been determined in order to use three different soil models in PLAXIS. The used soil models are Soft Soil Creep, Hardening Soil and the S-Clay1 model. The soil models and parameters were fitted by comparing the calculation results with the measured data. The used measured data are; water pressure development underneath the embankment, settlement of the embankment and horizontal soil deformation at two locations. The Soft Soil Creep model gave the best calculation results in comparison with the measured data. The used parameters in the Soft Soil Creep model were further investigated in the soil test module in PLAXIS. This module has been used to simulate real triaxial test data. The calculated displacement of the piles in PLAXIS and the measured displacements were compared to each other and showed good comparison at one location. Two different displacement patterns were recognized both in the PLAXIS calculation and the measured data. In the period close to pile installation when consolidation is the dominant process the maximum deflection of the pile occurs in the peat layer. In later stadia maximum deflection occurs at the top of the pile.

Student: K. Siderius Thesis Committee: Prof.ir. A.F. van Tol, Ing. H.J. Everts, Dr.ir. K.J. Bakker, ir J.F. Joosse, Ir F.J.M. Hoefsloot

For further information please contact the section Geo-Engineering, 015-2781880 Email: [email protected]

54 | Master’s Theses March 2012

4

Geo Engineering

Modelling and Effects of Rapid Impact Compaction

Due to the increased scale of dredging technology, dredged soil is often rapidly deposited on reclamation sites. As a result, there is less time to compact the sand in thin layers and compaction over thicker lifts is required. A promising technique called Rapid Impact Compaction (RIC) is able to achieve the compaction over these thicker lifts. It compacts the subsoil effective and fast from surface level. Cofra B.V. has developed its own Cofra Dynamic Compaction (CDC) machines based on the original RIC technique. The CDC technique itself has proven to be an efficient and sturdy alternative for the conventional dynamic compaction techniques and RIC methods.

The good compaction results of RIC (up to 7m) are not expected when influence depth is computed with the Menard & Broise (1975) equation, which predicts influence depth for dynamic compaction. Contractors using the RIC technique are often confronted with this formula/ method, which is actually incorrect for RIC. There are several unknown aspects about the RIC technique and its effects on the subsoil that require further research. The differences between the results are clear; the exact mechanisms on and in the subsoil that cause these differences are still undefined and no practical model has been developed to simulate the effects of RIC. At the start of this study the main goal was to attribute the different mechanisms of RIC, which contradict predictions of the Menard and Broise (1975) formula. But finally an avail-

able model from literature has been adjusted to simulate compaction in dry granular soil with the RIC technique. From literature study it is concluded that the densification model of Barkan (1962)/ Hergarden (2000) is a straightforward and applicable method to model RIC. It was used originally for estimating densification during sheet piling. The model uses a threshold acceleration amplitude below which no densification occurs. The threshold value depends on the initial relative density and a “Barkan” factor. The Barkan factor is dependent on stress level, strength level and type of soil. Initial relative density was obtained using correlations between cone resistance and relative density, applied on pre- and after CPT data. The estimation of vibrations uses straightforward empirical attenuation relations. Values for this relation were obtained from vibration measurements in depth and on surface level during RIC, also with different energy levels of the RIC hammer. The densification model uses an exponential relation to determine the final relative density; with the use of the occurring acceleration amplitude and threshold state of the soil. The model showed high inaccuracies and sensitivity. Results are considered to be quite reasonable within the field of dynamic geotechnics, also taking into account its straightforwardness. Inaccuracies occurred mainly due to: poor correlations between cone resistance and relative density correlations, imprecise derivation of the Barkan factor, inaccurate estimation of vibrations, heterogeneous soil conditions (silts and cementations) during validation and during measurements of model parameters and horizontal effective stresses build-up during and after compaction. It is recommended to refine the measured values and analyse the values of the Barkan factor for different soil conditions. Despite the deviation from the original problem statement, a qualitative attempt was still made to address the effective compaction of RIC compared to conventional DC. The constant dynamic state of the soil in between blows and the permanent contact between hammer and soil, were considered to be leading in the effectiveness of RIC. It is recommended to further research these differences

Student: J. Vink Thesis Committee: Prof.ir. A.F. van Tol, Ing. H.J. Everts, Ir. J.W. Dijkstra, Ir. D. Luger, Dr.ir. P. Meijers, Dr.ir. K.J. Bakker For further information please contact the section Geo-Engineering, 015-2781880 Email: [email protected]

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4

Geo Engineering



56 | Master’s Theses March 2012

5. Civil Engineering theses

Watermanagement

5

Watermanagement

Analytical Modeling of Salt Intrusion in the Kapuas Estuary

Introduction

Conclusions

In the city of Pontianak, located in West Kalimantan, Indonesia, a local drinking water copes with salinisation of the Kapuas Kecil in the dry period. Due to small discharge in both the Landak and Kapuas Kecil in this season, saline sea water intrudes into the estuary through dispersion and propelled by the tide. Together with Oasen, the drinking water company of the Gouda region in the Netherlands, a research plan has been developed to come up with solutions for this raw water problem. The modeling in this thesis has been based on the measurements I have set up and performed in the three times I visited Pontianak.

Objectives The main goal for this thesis is to take a step in the solution of the raw water problem in terms of salinity and create a model to predict salt intrusion based on discharge scenarios. Therefore an analytical approach was set out, based on salt intrusion theories of both Professor Savenije (TU Delft) and Kuijper & Van Rijn (Deltares). Moreover, a numerical approach was used by means of Delta Shell (beta-version), a new version of Sobek, to simulate tidal dynamics. (Unfortunately, a salt module in Delta Shell has not been developed yet)

Results Salinity was well-mimicked by theory of both Savenije and Kuijper & Van Rijn. Despite optimized inclusion of damping in the equations of Kuijper & Van Rijn, not much difference was shown in this case study. Tidal dynamics modeled with Delta Shell showed pretty strong damping based on Chezy values lower than expected (45 and 30 in the upstream meandering part of the Landak). Also high tidal wave celerity was observed in the results of Delta Shell.

Despite the rough dataset, both approaches gave interesting results; In terms of tidal dynamics, both approaches showed similar output. This confirms that an analytical approach based on before mentioned theories can be combined with a Delta Shell modeling approach. Also, both analytical theories proved to be able to be used in a predictive way in this estuary in terms of salt intrusion. The Chezy configuration is probably a result of the data used at the junction between Kapuas Besar and Kapuas Kecil. Only water levels could be observed due to tidal motion in this area of the estuary, while discharge, ideally, should be included as well. Research on the storage width in the estuary will bring down the tidal wave celerity.

Recommendations Since I was the first person to ever perform and combine measurements on tidal dynamics and salt intrusion in the Kapuas estuary, the amount of data is small. An integral measurement campaign in the whole estuary would not only supply the data required for further research, moreover it is essential to in the end run such a model on daily basis. Delta Shell is a nice improvement of the former Sobekmodel. However, without a salt module, it loses potential of a stand-alone operational program. With so much knowledge on board, Deltares should implement such a module while they are at it!

Student: F. Gevers Deynoot Thesis Committee: Prof.dr.ir. H.H.G. Savenije, Ir. C. Kuijper, Dr.ir. Z.B. Wang, Dr. S. Pande

For further information please contact the section Water Management, +31 (0)15 278 1646 Email: [email protected]

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5

Watermanagement

Moisture Recycling and the effect of land-use change

In this thesis work, we stepwise analyze land-use change effects on global moisture recycling and on the resulting precipitation of the ‘Challenge Program (CP) River Basins’ for the period 1997-2006. We investigate two land-use cases, one being the current actual landuse case and the second being the ‘undisturbed case’, using potential natural vegetation data and subsequently we compare them at a global scale. This is done by computing precipitation of continental origin differences caused by the associated continental evaporation differences between the land-use cases. The seasonal variations of both moisture fluxes are discussed by focusing on characteristic grid-cells. We observe that in regions, where intense irrigation takes place in the current land-use case, both continental evaporation and the resulting precipitation have increased compared to the potential natural vegetation scenario. On the other hand, certain regions like Western/Central Africa and South-eastern South America experience reductions in the range of 30-50 mm/yr of evaporation and 15-25 mm/yr of precipitation of continental origin (Figures 1 and 2). Among the basins examined, the Indus shows the highest increase in evaporation due to the land-use change and the Ganges-Brahmaputra the highest precipitation (of continental origin) increase, whereas in the Volta both fluxes are reduced by this change.

Figure 1: Global Annual Average Continental Evaporation Difference

Figure 2: Global Annual Average Continental Precipitation Difference values

We conclude that the topography and wind patterns play a very important role on the creation of the either positive or negative fluxes’ differences between the different land-use cases. When land-use change is combined with mountain ranges present in the study region the effect of local moisture recycling strengthens. However, when the change occurs at regions where the resulting moisture difference will finally be transferred to the oceans by the wind, no difference is caused in the moisture recycling of a land region.

Student: R. Nikoli Thesis Committee: Prof. H.H.G. Savenije, Ir. R.J. van der Ent, Prof. R.F. Hanssen, H. Hoff,

For further information please contact the section Water Management, +31 (0)15 278 1646 Email: [email protected]

59 | Master’s Theses March 2012

5

Watermanagement

Memstill for wastewater: Effects of surfactants in the feed solution

Introduction Water has always been one of the most basic needs of human, and is becoming increasingly critical with the growing human population. Therefore, a new technology to obtain clean water effectively and efficiently is always desirable. Membrane distillation (MD) is a recent promising technology to provide very clean water at very low cost. Memstill ® is a specific MD application that has significant advantages over typical MD processes, and has proved its feasibility in desalination. However, the key obstacle in its applicability to wastewater treatment is the presence of surfactants which may lead to membrane wetting.

Research My research aims to study the effects of surfactants on the Memstill process. My literature review showed that the membrane may be wetted due to fast surfactant adsorption on the liquid-air and liquid-solid interfaces, lowering breakthrough pressure; as well as slow surfactant adsorption on the solid-air interface due to diffusion, leading to imbibition. Based on these findings, I developed theoretical predictions of the effects of breakthrough and imbibition in the Memstill context. Finally, I conducted experiments on breakthrough pressure’s dependence on surface tension as a result of the fast processes, and Memstill performance over extended time as a result of the slow process, in order to verify the theory and assess the feasibility of Memstill for wastewater.

breakthrough pressure than predictions. With typical surface tension of wastewater, the breakthrough pressure is above 5 bar. During the first few days of operation, Memstill displays very good performance. However, wetting of the membrane occurs after several days of operation due to the slow adsorption process that causes imbibition.

Conclusions Fast adsorption processes are not critical to Memstill. Initially the process performs well. The slow adsorption process is fatal to Memstill, rendering it ineffective. At present, Memstill is not suitable to treat wastewater containing surfactants without further enhancement to the membrane.

Recommendations As fast adsorption processes are not critical, a new breakthrough pressure study with the membrane presaturated with surfactant adsorption is suggested. Adsorption experiments should be carried out to determine the isotherms of popular surfactants. This will enhance the ability to predict wetting in Memstill operations. I recommend studying the possibilities of pre-treatments such as electrodialysis or ion-exchange, since ionic surfactants can be retained, reducing the risk of wetting to Memstill.

Results The topic of interest is complicated with many interacting phenomena. To facilitate understanding, I developed a scenario diagram connecting different possible scenarios in which Memstill may or may not be applicable; as well as an influence diagram establishing relationships between different properties of different process components and how they ultimately influence wetting or non-wetting. From the breakthrough pressure experiments, the membrane characteristic constants were determined. The Memstill membrane can sustain slightly higher

Student: N.T.T. Hung Thesis Committee: Prof.ir. L.C. Rietveld, Dr.ir. Norbert Kuipers, Dr.ir. P.J. Visser, Assoc.Prof. P. J. Chen

For further information please contact the section Water Management, +31 (0)15 278 1646 Email: [email protected]

60 | Master’s Theses March 2012

5

Watermanagement

Biofouling and organic micropollutants rejection

Introduction

Results

Previous studies have identified the main rejection mechanism of organic micropollutants by high pressure membrane filtration systems, resulting in a mathematical model that predicts the removal efficiency. The model includes three solute-membrane interactions: steric hindrance interactions, electrostatic charge interactions and affinity interactions. The goal of this study was to characterize the modification in surface properties that biofouling exerts when adhering onto nanofiltration (NF) membranes and to investigate how these modifications alter the interaction between membrane surfaces and organic micropollutants.

Research At KWR, Nieuwegein, experiments were carried out using spiral wound NF membranes which were first heavily biofouled and then subjected to rejection tests and membrane characterization. To identify and compare the solute-membrane affinity interactions of clean and biofouled membranes, a protocol allowing the determination of the surface tension of biofouled membranes was developed and validated. The surface tensions were determined by measuring contact angle of different probing liquid droplets on clean and biofouled membrane surfaces and applying the YoungDupré equation. Three methods were applied and evaluated in which the membranes were dried, immersed in water and maintained fully hydrated.

The resulting surface tensions showed that biofouling makes the surface more hydrophilic. The membrane surface charge (zeta potential) remained unchanged and the average membrane pore size decreases, due to biomass accumulation, as biofilm was growing. These changes in surface characteristics affected the rejection of the positively charged organic micropollutants while no significant effect was observed for the neutrally and negatively charged solutes.

Conclusions In conclusion biofouling negatively altered the rejection behavior of positively charged micropollutants. With an increased solute-membrane affinity due to biofouling more partitioning of positive micropollutants into the membrane took place providing a decrease in the rejection.

Student: N.T. Quach Thesis Committee: Prof.dr.ir. L.C. Rietveld, Prof.dr.ir. A.R.D. Verliefde, Prof.dr.ir. P.W. Appel, Dr.ir. E.R. Cornelissen, Dr. S. Botton, Ing. D.J.H. Harmsen For further information please contact the section Water Management, +31 (0)15 278 1646 Email: [email protected]

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5

Watermanagement

Operationalization of SoilDTS

Introduction In the last ten years Distributed fiber optic Temperature Sensing, often shortened to DTS, has been developed as a useful tool for all sorts of hydrological research. Within this wide span of topics several studies on soil thermal properties and soil moisture using DTS are performed, so-called SoilDTS. SoilDTS is split in two methods: PassiveDTS, where the response of soil temperatures to the diurnal signal in R n is measured; and ActiveDTS where a heat pulse is applied to the cables using the electrical resistance of its steel armoring.

Methods From March to October 2011 three fiber optic cables at 1, 6 and 11 centimeters are plowed in a grass plot in Delft, The Netherlands. From March to May 2011 PassiveDTS measurements are conducted and in September 2011 a four day ActiveDTS campaign took place. For the passive measurements an inversion method is used to calculate diffusivity from soil temperature using the thermal diffusion equation. With a decagon KD2 probe a relation between thermal conductivity and soil moisture is derived from which soil heat flux (SHF) is calculated. During the ActiveDTS campaign 30 minute heat pulses of 6 W/m are applied to the steel armoring of the cable. The response to this heat pulse measured in that same cable is used to calculate thermal conductivity which leads to SHF profiles. SHF estimates are finally compared to other parameters of the surface energy balance.

Results The PassiveDTS method gives accurate estimates of surface heat flux profiles. From the thermal conductivity vs. soil moisture content relation also soil water content can be calculated. These calculated values are consistent with measured values from an in-situ EC5 moisture probe. The relation between thermal conductivity (K) and soil moisture is essential for the success of the PassiveDTS method. This relation is very hard to derive from existing models like Johansen75 or Campbell but in this research it is shown that deriving this relation manually

is fairly simple and rewarding when accurate K estimates are preferred. The four day ActiveDTS campaign gave very promising results for this method. From the temperature response to the applied heat pulses, thermal conductivity is calculated using the single-needle-heat-pulse-probe method used in commercially available single-needleheat-pulse-probes like the Hukseflux TP02. One crucial aspect is the determination of the exact amount of heat applied to the soil. The measured temperature inside the cable can be different from the temperature on the outside of the cable. The SHF estimates are sufficiently accurate to use in energy balance closure calculation. This is valuable for evaporation calculations or satellite reference measurements for instance used in agricultural research.

Conclusion and recommendations SoilDTS is a very promising and useful tool to determine and monitor soil thermal properties and soil moisture. PassiveDTS is still dependent on accurate reference measurements of thermal conductivity and soil moisture. ActiveDTS can be a tool that is capable of deriving thermal conductivity without extensive reference measurements. Further research on the effect of cable insulation on the applied heat pulse to the surrounding soil is necessary but can definitely be rewarding.

Student: J.H.A.M. Jansen Thesis Committee: Prof.dr.ir. N.C. van de Giesen, Dr.ir. S.C. Steele-Dunne, Prof.dr. M. Menenti

For further information please contact the section Water Management, +31 (0)15 278 1646 Email: [email protected]

62 | Master’s Theses March 2012

5

Watermanagement

The world’s freshwater resources are threatened

The world’s freshwater resources are threatened. The main causes are population growth and climate change. These factors also impact the freshwater resources along the coast. The appearance of saltwater in the coastal zone makes the problem even more complicated. Results of research on two concepts that enlarge the freshwater resources along the coast are presented. Along the coast, freshwater is being lost to the ocean. This happens through freshwater seepage from the freshwater lens. A freshwater lens is presents under the dunes and is formed by precipitation. Freshwater seepage, or outflow, is a process that drains the precipitation that is not used or extracted. It means that in principle the net recharge is also flowing out at the edges of the system.

Concepts The outflow is a loss in the system. Two concepts are developed that intercept the outflowing water. The first concept is the laguna concept. In this concept a laguna is created between the original shoreline and a newly created dam at some distance from the coast. The laguna will fill with outflowing water, making it usable for drinking water production. The second concept is the barrier/drain concept. In this concept a physical vertical barrier is installed close to the shoreline. The extra introduced resistance to flow prevents freshwater to flow out and creates higher heads. The head is reduced by taking out water through a drain, in that way collecting the previously outflowing water.

Results and Conclusions The result for the barrier concept is that in the case of clay layer up to almost 95% of the potential outflow can be intercepted. That is for the case that the barrier is installed with the toe in the clay layer. The drain discharge depends mostly on the drain level and the barrier depth. For the case that there is no clay layer, the amount of water that can be captured is only 65%. With the laguna concept 90% of the potential outflow can be captured. The three parameters that influence the results most are the width of the laguna (i.e. the distance between the shoreline and the offshore dam), the water level in the laguna and the combined hydraulic conductivity and resistance of the aquifer. An analytical solution has been derived for the laguna concept. The analytical solution is compared to the numerical model results. The numerical model follows the analytical model almost perfect for most cases for which the solution is valid. The validity of the analytical solution for other combinations of the parameters still has to be investigated. The analytical solution is used to determine the parameter sensitivity for the three parameters mentioned earlier (kc, W L and h *).

Method The concepts are tested on a fictitious island of 3 km wide, with and without a clay layer. The island is modeled using the computer code of MODFLOW. To be able to incorporate density differences between fresh and saltwater, the SEAWAT and SWI packages are used. The concepts are evaluated on the amount of outflow they can capture in relation to what would flow out when no changes were made to the system.

Student: M. Hegnauer Thesis Committee: Prof.dr.ir. T.N. Olsthoorn, Dr.ir. M. Bakker, Dr.ir. J. Timmermans, Ir. J.H. Peters, Ir. F. Schaars

For further information please contact the section Water Management, +31 (0)15 278 1646 Email: [email protected]

63 | Master’s Theses March 2012

64 | Master’s Theses March 2012

5. Civil Engineering theses

Transport & Planning

5

Transport & Planning

Study of evacuation behaviour during a flood

Recent history has shown a large number of natural hazards, most likely as a result of global warming. Research on climate change predicts that the rise in hazards will continue in the near future. As complete prevention of these hazards is nigh on impossible, limiting the impact of future catastrophes is the most viable strategy. Evacuation can be seen as one of the most tangible measures against these threats, and moreover has the most links to the field of transport & planning.

Analysis of the acquired data has shown the influence of each factor of the framework. In terms of location parameters, hazard distance and level of hazard information were important factors influencing the decision to evacuate (the threat level increased by an approaching hazard and detailed available information). Another important attribute was the evacuation order issued; a mandatory and recommended evacuation order lead to higher evacuation rates.

This research was carried out to gain a more detailed understanding in the behaviour of evacuees; results that will help authorities in optimizing hazard strategies. More concretely, this research focussed on the decision to stay or leave a threatened area, and the choice of the preferred evacuation route. This behaviour was captured by means of a discrete choice experiment whereby participants were confronted with several fictitious flood scenarios.

The various travel factors included in the framework had a relatively small effect on the behaviour of an evacuee; only the damage to the road network resulted in an increase of the likelihood of evacuation. For evacuees using public transport, the waiting time was the only relevant trave attribute; a long waiting time resulted in longer response times and thus lower evacuation rates. In terms of personal parameters, the particular gender of an evacuee caused differences in evacuation behaviour (females being more risk-averse resulting in higher evacuation rates). The other factors (age, hazard experience, education) were deemed not significant, although it is expected this is in large part due to a homogenous sample group (mainly students). Regarding route choice, evacuees showed risk-averse behaviour; opting for a safe route instead of one with a short travel time. This was particularly the case in situations with a high threat level. At lower threat levels, the travel time became more relevant (a preference for routes with short travel times).

Fig. Decision framework of an evacuee. A decision framework was created including most of the factors indentified as relevant in previous evacuation studies. Roughly, they could be divided in two groups; location parameters, describing the physical characteristics of the hazard scenarios, and personal parameters describing the traits of an evacuee.

Student: S.L. Hek Thesis Committee: Prof.dr.ir. S.P. Hoogendoorn, Dr.ir. J.W.C. van Lint, Ir. M. van den Berg, Ir. P.B.L. Wiggenraad, Cr. E.J.E. Molin. For further information please contact the section Transport & Planning, 015 2789341 Email: [email protected]

66 | Master’s Theses March 2012

6. Last year’s Theses

6

Last year’s Theses

Master’s Theses October 2011

Civil Engineering theses Building Engineering Application of Higher Strength Concrete in Tubular Structures Student: H. Balbaid Sustainable and Durable Redevelopment Student: E. Bilardie Optimising the design of a steel substructure for offshore wind turbines in deeper waters Student: F.P.M. van Gerven Testing the application of CFD for building design Student: S.R. Hunte

Fatigue damage in the orthotropic steel deck with respect to the trough-to-deck plate joint in between the crossbeams Student: J. Liao Automatic Buckling Checks on Stiffened Panels Based on Finite Element Results Student: O. Hillers Autogenous shrinkage of cementitious materials containing blast furnace slag Student: R.M. Mors

Hydraulic Engineering Morphological modeling of the Atrato river delta in Colombia Student: S. Post

Ultra High Performance Concrete in Large Span Shell Structures Student: R.N. ter Maten

Navigability at an unstable bifurcation Student: F.C.R. Melman

Glass Columns Student: E. Ouwerkerk

On the morphodynamics of Lagos Harbour Student: V. Ballendux

Fatigue Design of FSPO topside details Student: B. Siegler

Tidal divides Student: J. Vroom

Super high-rise in Rotterdam Student: U.M Winter

Risk-based control of salt water intrusion for the RhineMeuse Estuary Student: M. Zethof

Triple-layer membrane structures - Sound insulation performance and practical solutions Student: J.J.E. de Vries

Structural Engineering

Modelling Sediment Transport in the Swash Zone Student: A. van Rooijen Dune erosion near sea walls Student: B. de vries

Shearforce in immersed tunnels Student: D.A.W. Joosten

System description Noord-Holland coast, a review of the nourishment strategy applied. Student: R. Pot

Mega Floating Concrete Bridges Student: A.H. Saleh Communicating ‘structural’ design options Student: T.K. Uijtenhaak Shear Redistribution in Solid Concrete Slabs Student: J. Falbr The effect of the increase of concrete strength in time on the failure mechanism of beams and one-way slabs Student: L.F. Soto

Modelling decadal barrier island behavior Student: K.W. Pruis Notional Permeability of breakwaters Student: R. Kik Earthquake analysis of quay walls Student: J.W. Liang

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Preparing a long term management plan for the future of the Slufter Student: R. Heerema

Rainfall fed inundation in greenhouse dominated polders; Research of water system assessments Student: B.C. Albers

The behaviour of a moored oil tanker in the Port of Leixões, Portugal. Student: M. van der Wel

Prediction of temperature distribution in a Drinking Water Network Introduction Student: L. Magda

Interaction between loaded barges and bed material Student: R. J. Lenselink

A new suit for the IJsselmeer Student: J. Talsma

Goederenvervoer over water Student: R. van Liere

A fresh-keeper for Noard Burgum Student: M.J.H. van der Valk

Preliminary study of the flushing operations in the Langmann reservoir, Austria Student: V.J.E. den Boer Process-based modelling of coastal dune development Student: M.C. Muller

Transport & Planning The use of probe data from consumer GPS navigation devices for the analysis of controlled intersections Student: A.M. Meijer

Modelling the interaction between morphodynamics and vegetation in the Nisqually River estuary Student: M. Monden

Geo-Engineering Het opstellen van een richtlijn voor partieel funderingsherstel Student: S. De Lange Time dependent processes on passive loaded piles Student: K. Siderius

Watermanagement Land classification based on hydrological landscape units Student: S. Gharari Urban surface water quality enhancement. Student: M.R. van Dieren Unembanked Areas – A risk assessment approach Student: M. Wolthuis Performance assessment of tree-based model predictive control Student: P.M. Stive

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Master’s Theses June 2011

Civil Engineering theses Building Engineering Structural feasibility of the Rotating Tower Dubai Student: P. den Besten Double curved precast load bearing concrete elements Student: B. Janssen The effect of steel plate girders with a high slenderness upon the fire resistance Student: R. Wiersum Parkeerkelder met een pneumatisch caisson Student: S.P. Rodrigues Monteiro

Hydraulic Engineering The cause of coastal erosion on a nourished beach in Kololi, The Gambia Student: E. Bijl Influence of the armour layer and core permeability on the wave run-up Student: P.J.M. van Broekhoven Feasibility study on the use of a floating breakwater to protect a new artificial beach in Balchik, Bulgaria Student: R. Drieman Design of berth n.12 in the port of Ventspil, Latvia Student: P. Gatta

Verlevendiging van de binnenrotte door multifunctioneel marktsysteem Student: M.Zoons

Mooring facility ‘Cruiseport The Hague’ Student: H.J. van der Giessen

Cellular beam-columns in portal frame structures Student: J.G. Verweij

Space intensification EMO-peninsula Student: T.M. Henneveld (MSc Hydraulic Engineering)

Structural Engineering

Modelling the equalizing process of rockfill dumps with a plough Student: W. Kranendonk

Plate buckling in design codes Student: M. van der Burg

Morphodynamic analysis of the Ecobeach project Student: M. de Lange

Wind load and high-rise: Student: N. Narain Loading capacity of laterally restrained prestressed concrete slabs Student: R.F.C. de Rooij The effects of the interaction between the substrate and the superstructure of the buildings of project Erasmuspoort Student : R. Soemeer Extension and Verification of Sequentially Linear Analysis to Solid Elements Student: L.O. Voormeeren Stability of a concrete pedestrian bridge with load bearing railings Student: V.M. Weidema Ultra High Performance Fibre Reinforced Concrete for bridge constructions Student: L.W.H. Bouvy

Probabilistic design of settling basins for environmental compliance Student: W. de Lange Verzandingsprobleem in de vluchthaven Wijdenes Student: E. Lee Comparison of quay wall designs in concrete, steel, wood and composites with regard to the CO 2-emission and the Life Cycle Analysis Student: T. Maas Providing current forecasts for the 2012 Olympic Sailing Competition Student: S. Poortman The Effects of The Ike Dike barriers on Galveston Bay Student: M. Ruijs Relatie tussen unity check en faalkans Student: J. De Vlieger

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Invloed van zandeigenschappen op het piping proces Student: R. van der Zee The morphological effects of Sediment diversions on the Lower Mississippi River Student: M.Bos Stroming van beton in diepwanden Student: J. Mulder

Hydraulic Engineering – COMEM Domain Modeling the Evolution of the Wax Lake Delta in Atchafalaya Bay, Louisiana Student: K. Hanegan The appraisal of climate adaptation measures and coastal management strategies for Durban, South Africa Student: M. A. Geldenhuys Impact of acces of channels geometry on wave penetration in harbours Student: C. G. Mardones Low Frequency Wave Resonance on Fringing Reefs Student: A. W. Mackay Pomeroy

Integrated water management from the treasurer’s perspective Student: J. van Leeuwen Subsurface abstraction in the Amsterdam Watersupply Dunes Student: R. Martens Groundwater dynamics landslides in varved clays Student: J.E. van der Spek

Transport & Planning Micro dynamisch verkeersmanagement Student: I. Bouma Effect van verkeerslichten op turborotondes Student: B. Granneman Line design of the future Student: N. Guis Redesign of the bus station Groningen assisted by a new simulation tool for bus stations Student: J.J.F. Hoogenboom MSc. Futures of Rotterdam South Student: R. Hoogerwerf

Geo-Engineering Experimenteel modelleren van horizontale belastingen op grote diameter monopaal fundaties in zand Student: A. Alderlieste

De overgang van 80 km/uur naar 50 km/uur op de grens bebouwde kom Student: M. de Jong

Piled embankment with Geosynthetic Reinforcement Student: T.J.M. den Boogert

Separation of Freeway Traffic Flows by Dynamic Lane Assignment Student: A.M.G. Soekroella

Grondvervormingen ten gevolge van het maken van bouwputten Student: J. Kimenai

Regional effects on road safety of the RijnlandRoute Student: L.M. van Dijk

Toepassing spanningspadmethode op een horizontaal gronddruk vraagstuk Student: G. Peeters

Around the metro - Research intro the potencies of the metro stops in Rotterdam Student: R.G. van Huet

Negative Skin Friction; Design challenges in Singapore Student: P.J. Spruit

Watermanagement A Decision-Support System based on Real Time Control and Data Assimilation Student: A.L. van Breukelen

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Master’s Theses February 2011

Civil Engineering theses Structural Engineering

Hydraulic Engineering Integral Design of Work Channels and Basins Student: T, IJsebeart Dredging history of the river Waal and expected future dredging works Student: J.S. Bardoel

Living Tree Buildings Student: Anne Nuijten Application of Ultra High Strength Concrete in LNG Terminals Student: Michel Kortenaar Mechanical behavior of bridge bearings of concrete bridges Student: M. de Boer

Numerical modeling of wave run-up on a dike Student: I.C. van den Bosch Analysis of costs in new terminals investments Student: C. van Buuren Shell factors for piles subjected to horizontal soil displacements Student: Erik den Arend

Winter damage of porous asphalt Student: S.A. Mohan Snap through of large shield driven tunnels Student: T.G. van der Waart van Gulik Traffic induced bearing loads and movements of a steel plate-girder bridge Student: V. Bos The optimization of tripod substructure and its application to two different topsides Student: Wenchao Wang Human Induced Lateral Vibration of Bridges Student: D. Karagiannis

A comprehensive assessment of Multilayered Safety in flood risk management Student: Frouke Hoss The Gevelco quay wall Student: D. Grotegoed “Feasibility study of a Climate Dike” Student: Larissa Smolders Flood defence town centre Dordrecht Student: M. Hinborch Long-term morphological modelling of the mouth of the Columbia River Student: Emiel Moerman

Building Engineering Covering A28 highway at Amersfoort Student: S.L. Huneker The elevated metro structure in concrete, UHPC and composite Student: R.J.A. Kenter The sustainable refurbishment of bk city Student: M.K. Prodromou A timber bearing structure for ‘Concept House’ Student: A.D. van Wijngaarden

Dynamic behaviour of tunnel elements during the immersion process Student: G.W. Nagel Stimulering provinciale binnenvaart door verkeersmanagement en aanpak knelpunten Student: C. van der Hoog Gaining new insights regarding traffic congestion, by explicitly considering the variability in traffic Student: O.M. Miete Modelling nearshore currents driven by waves and set-up gradients Student: P. van de Linde

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Morphological Impact of Coastal Structures Student: R. van der Hoeven

Transport & Planning

Post-trenching with a trailing suction hopper dredger Student: K. van de Leur

Gaining new insights regarding traffic congestion, by explicitly considering the variability in traffic Student: O.M. Miete

Port Design Student: R.A.R. Heuts

Accelerating the introduction of electric bicycles Student: Jeroen Loijen

Numerical modelling of turbidity currents in submarine channels Student: Anne Ritsema

Geo-Engineering Laterally Loaded Piles, Models and Measurements 48 Student: J. Ruigrok

Watermanagement Validation of SMOS satellite data over Ghana and Burkina Faso Student: A. Poelstra Onderzoek naar verbrakking Polder Westzaan Student: I. Gozuberk Analyzing the effects of large-scale green roof implementation in Singapore Student: J. van Spengen Clogging of permeable pavements in semi-arid areas Student: M. Amirjani Observing tidal slack in the Scheldt estuary Student: M. Lievens Low cost disdrometer Student: S.A.P. de Jong Swale filter drain system: The inflow – discharge relation. Student: E. A. Donkers Conditioning of aggressive water Student: J.C.J. Gude

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Master’s Theses October 2010

Civil Engineering theses Structural Engineering Structural Failure in the Netherlands Student: W.F. Boot Special Nodes in Ultra High Performance Concrete Student: Hasan Han Corrosion of steel reinforcement in 12 years old concrete: Inspection, evaluation and electrochemical repair of corrosion Student: J. Pacheco Farias Design of walls with linear elastic finite element methods Student: M. Romans V-shaped pylon concept Student: J. van Weerdenburg The feasibility of full 3D modeling of concrete viaducts Student:N.W. Kostense

Design tool for determining the sustainability of structural designs Student: F.T. Tool Crack formation in structural slabs on underwater concrete Student: W.H. van der Woerdt

Hydraulic Engineering “Layout design for greenfield port Filyos” Student: L.B. Donders Undesired reshaping of exposed core material Student: P.H.M. Mulders Experimental research on spatial distribution of overtopping Student: A. Lioutas Sharp bend flow Student: A. van Sabben Analysis of the Carbon Footprint of coastal protection systems Student: A.L. Labrujere

Autogenous and drying shrinkage Student: Jan van Capellen Phenomenological modeling of ice induced vibrations of flexible offshore structures Student: H. Hendrikse The effect of the introduction of the eurocode on the safety level of excisting platebridges Student: Frank Schotman

An analysis of vessel behaviour based on AIS data Student: Thijs de Boer Tidal influence on sediment transport and bed level in the river Merwede Student: A.L. de Jongste (MSc Hydraulic Engineering) Aeolian transport on beach based on field measurement on the Dutch coast Student: Marion Coquet (Coastal engineering)

Building Engineering Damage investigations in concrete buildings Student: Carolina Miró-Downey Sustainable Facade for the Energy museum Student: S. Esmailzadeh Structural feasibility study and design of a portable stadium Student: A.H. den Hollander “Parametric Collaboration Tool” from architectural input to engineering output Student: Oswald Verbergt

“The influence of core permeability on armour layer stability” Student: H.D. Jumelet Behaviour of segment joints in immersed tunnels under seismic loading Student: Ruben van Oorsouw Numerical modeling of sediment transport over hydraulic structures Student: Vincent Vuik

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Cross-shore morphological response on Chaland Headland due to Hurricanes Gustav and Ike Student: S.N. Kuiper

Transport & Planning Dynamic Speed Limits: Extension and Application Student: Ilse Schelling

Cobble Sea Defence: Hydraulic Interface Stability of Sand underlying a Single Filter Layer Student: Arthur Zoon Model a dynamic equilibrium of yearly averaged salinity in the Pontchartrain Basin Student: S. van den Heuvel Failure of rubble mound breakwater’s armor layer Student: unknown Behaviour of nourishments in quasi 3-dimensional graded sediment models Student: unknown Pilot Sand Groynes Delfland Coast Student: unknown Dong Lam Cement Factory Student: W.A. (Wouter) Broersen Probablistisch diepteontwerp voor binnengebied haven Rotterdam Student: Y. Abdelouarit New Profile for the Amsterdam-Rhinecanal Student: L. Lievense Master plan Porto Romano Bay, Albania Student: M.K. Kersten

Geo-Engineering Bentonite cavities in diaphragm walls Student: A.J. Lubach The adaptation of the method URUP for the Netherlands Student: A.J. Beijer Process and stability of slow moving landslides Student: Eva Johanna Sloof Modelling horizontal soil deformations Student: C.W.J. te Boekhorst

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Research Groups and professors within the faculty

Research groups and professors within the faculty of Civil Engineering and Geosciences

Specialisation

Name

Telephone 015-27. . . . .

Structural Engineering Structural Mechanics Research Group Construction mechanics Dynamics Numerical mechanics AVL Wave Dynamics

Prof. J.G. Rots Prof. A.C.W.M. Vrouwenvelder Prof. L.J. Sluys Prof.dr. A. Metrikine

83799 84782 82728 84749

Materials and Environment Research Group Betonmodellering & Materiaalgedrag Experimental Micromechanics Materials and Durability Resource Engineering & Materials Recycling

Prof. K. van Breugel Dr.ir. H.E.J.G. Schlangen Prof.dr. R.B. Polder Prof.dr.ir. P.C. Rem

84954 86535

Road and Rail Engineering Research Group Road Construction Raiway Engineering

Prof. A.A.A. Molenaar Dr.ir R.P.B.J. Dollevoet

84812

Structural and BuildingEngineering Research Group Concrete modelling & materials Timber structures Steel Structures Constructive Design

Prof.ir. A.Q.C. van der Horst Prof.dr.ir. J.W. van de Kuilen Prof. F.S.K. Bijlaard Prof.dr.ir. R. Nijsse

87014 82322 84581

Design and Construction Processes Integral Design, Maintain and Operate of Civil Infrastructures Prof.dr.ir. M.J.C.M. Hertogh

83617

84921

Hydraulic Engineering Fluid Mechanics Research Group Environmental Fluid Mechanics Fluid Mechanics Sediment Dynamics Physical Oceanography

Prof.dr.ir. G.S. Stelling Prof.dr.ir. W.S.J. Uijttewaal Prof.dr.ir. J.C. Winterwerp Prof.dr. J.D. Pietrzak

85426 81371 84582 89455

Hydraulic and Offshore Engineering Research Group Probabilistic design and Hydraulic Structures Coastal Engineering Ports and Inland Waterways River morphology & River Engineering Morphodynamics of Lagoons and Estuaries

Prof. J.K. Vrijling Prof. M.J.F. Stive Prof.ir. T. Vellinga Prof. H.J. de Vriend Prof.dr.ir. Z.B. Wang

85278 84285 85075 81541 85075

Prof. F.H.L.R. Clemens Prof.dr.ir. J.B. van Lier Prof.dr.ir. W.G.J. van der Meer Prof.dr. G.J. Medema Prof.dr.ir. L.C. Rietveld

83347 81615

Water Management Sanitary Engineering Research Group Sewerage Environmental Waste Water Treatment Innovative Water Technologies Water and Health Urban Water Cycle Technology

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89128 84732

6

Last year’s Theses

Specialisation

Name

Telephone 015-27. . . . .

Water Resources Research Group Hydrology Water Management Water Resources Management and Earth Observations Groundwater Exploration Experimental Hydrology Water Resources Management and Earth Observations Science System Assessement

Prof. H.H.G. Savenije Prof. N.C. van de Giesen Prof.dr. W.G.M. Bastiaanssen Prof. Th. N. Olsthoorn Prof.dr. S. Uhlenbrook Prof. Bastiaanssen Prof. W. van Vierssen

81433 87180 85717 87346 82110 85717 87346

Prof.dr.ir. B. van Arem Prof.ir. F.C.M. Wegman Dr. R.A. Zuidwijk Prof.ir. L.H. Immers Prof. F.M. Sanders Prof. S.P. Hoogendoorn

86342

Prof.dr. G. Bertotti Prof. S.M. Luthi Prof.dr. S.A. Petersen Prof.dr. J.J.G. Reijmer

86025 86019

Prof.dr. P.L.J. Zitha Prof. W.R. Rossen Prof.dr.ir. J.D. Jansen

86033 86038 87838

Prof. W.A. Mulder Prof. C.P.A. Wapenaar Prof.dr. E. Slob Vacancy Prof.dr. S.A.P.L. Cloetingh

83666 82848 88732

Geo Engineering Research Group Soil Mechanics Foundation Engineering Underground Space Construction

Prof. M.A. Hicks Prof. A.F. van Tol Prof. J.W. Bosch

87433 85478 82844

Geosciences & Remote Sensing Research Group Remote Sensing of the Earth Atmohsphere

Prof.dr. P.F. Levelt

Transport & Planning Transport Modelling Traffic Safety Transport and Traffic Networks Traffic, Infrastructure Infrastructure Planning Traffic Management

83346 81780 85475

Geoscience & Engineering Applied Geology Research Group General Geology Production Geology Geoscience Integration Carbonate Sedimentology

86033

Resource Engineering Research Group Petroleum Engineering Research Group Oil- and Gas production systems Reservoir Technology Reservoir Systems & Control Applied Geophysics and Petrophysics Geophysical Imaging Methods Technical Geophysics Geophysical Electromagnetic Methods Natural Resource Engineering Environmental and Resources Techtonics

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