The Meuse is a river in West-Europe which rises at the Langres Plateau and flows from France through Belgium and the Netherlands. The river has always been an important shipping route, even though its navigability has been problematic in the Netherlands. To solve this problem seven weirs were constructed in the Dutch part of the Meuse. They are located at Borgharen, Linne, Roermond, Belfeld, Sambeek, Grave and Lith. Weirs are hydraulic structures and mainly control the upstream water level to allow for sufficient depth for shipping. Structures such as weirs generally have a technical life span of 100 years, and because the Meuse weirs were built 100 years ago they are up for replacement. Rijkswaterstaat wishes to have uniformity in the designs of the next Meuse weirs. This decreases the amount of unique components which in turn leads to the reduction of repair and maintenance costs.

The main objective of this thesis is to determine the most cost-efficient maintenance strategy for the next generation Meuse weirs. Part of the objective of this study is also to determine the influence of ship collisions on the availability and costs of weirs. In this thesis a case study is used to set up the analysis. The case study consists of two weir alternatives that were proposed as the replacement for the weir in Grave.

Based on the results for both the availability and costs of both maintenance strategies in this report it seems that the preventive maintenance strategy performs better than the corrective maintenance strategy for both weir alternatives. The availability under preventive maintenance is higher and the total costs (maintenance costs and repair costs) are lower under preventive maintenance. The availability of the weirs are mostly influenced by the failure mechanism of ship collision and the weir component “hydraulic aggregates”. The largest contributor to the maintenance costs are the hydraulic cylinders and for the repair costs the most significant contributor are the hydraulic aggregates. Ship collisions seem to influence the availability greatly, but has limited influence on the repair costs of the weirs.

Over the past decades an increase in underground construction is observed. Deep excavations are among the structures used for underground construction. The construction of such structures often affects nearby existing structures and causes possibly even damages.
The prediction of these damages is usually done by following these steps:
1. Determining the free-field ground displacements
2. Imposing the displacements on the structure
3. Determining the deformations of the structure
4. Assess potential damages following these deformations
The ground and the structure are often modelled separately taking no (LTSM) or a factor (Relative Stiffness Method) into account for interaction between soil and structure. Taking no interaction into account is particularly conservative when looking at vertical displacements. The non-linear behaviour of structural elements is neglected by these methods. This could lead to errors when assessing deformations of a masonry building due to the extreme non-linear behaviour of masonry structures.
The objective of this thesis is to get a better understanding of the effect of deep excavations on adjacent (piled buildings) by using integrated 2D modelling. This is done by remodelling the construction of the building pit in PLAXIS.
Based on the analysis performed in Section 4 the load on the pile is the largest contributor to the vertical and horizontal displacements of the pile relative to the soil around the pile. The diameter and stiffness of the pile are also very important factor determining the vertical movement of the pile.
The difference in the soil between a free-field situation and a situation with foundation piles (and a building) the piles stiffen the soil around the piles. Especially, when these piles are in a group. This effect increases when the piles are coupled by a structure. Vertical displacements are more smeared out over the length of the pile. This is less the case for horizontal displacements. Foundation piles undergo negative skin friction as a result of the settlements of the upper soil layers leading to stress in the soil beneath the pile tip. The stress in the soil beneath piles increases with increasing load and skin friction on the pile. This increased stress results in more horizontal stress, which in close proximity to a retaining wall could lead to increased deformations in the retaining wall and therefore the soil.
The results of the numerical calculations and the analytic calculations are analysed and compared in Section 6. In the numerical models both linear elastic as non-linear material properties have been assigned to the masonry building façade in different models. The numerical model with linear elastic material properties for masonry showed stiff response of the building to the induced soil deformations, underestimating the potential damages. The numerical model with non-linear material properties assigned to masonry showed more realistic results. These results are in line with the established analytical models.
Integrated numerical modelling could be a viable solution for future projects where potential building damage is assessed next to deep excavation. it could help to identify weak points within a structure which need addressing during the construction of an adjacent deep excavation. This study has shown that it is possible to do damage assessment in a fully integrated model. The important factors in assessing such projects are the overall soil deformation. Secondly, the relation between the soil and foundation of the structure needs to be analysed. Thirdly, the interface between the foundation and the structure is important.

The combination of continuous sea level rise, and more frequent extreme river discharges will become a rapidly developing problem for the Rhine-Meuse delta over the course of the next century. The current Dutch delta management policy mostly revolves around the consistent improvement of the existing dikes to account for the increasing water levels in the region. An alternative solution to this problem is the Delta21 project. The Delta21 project proposes the construction of a large scale storage lake, and a high capacity pumping station at the Dutch coast. The project is meant to allow for the simultaneous closure of the storm-surge barriers on the Dutch coast, while actively discharging river water that would normally be pilling up behind the closed barriers. The Delta21 project foresees it will be able to save up to 5billion euros by the end of the century in dike reinforcement costs. In order to enable the flood safety operation of the Delta21 project, the project also requires the construction of a new storm-surge barrier in the Haringvliet ebb-tidal delta, roughly 10km away from the current Haringvlietsluices. The objective of this thesis is the conceptual design of the new Delta21 storm surge barrier, the New Haringvliet barrier. The aim of this design process is to identify critical design components, and requirements that could potentially be hurdles in the development of the New Haringvliet barrier, as well as the overall Delta21 project. For the hydrodynamic design of the barrier, a schematized 1D hydrodynamic model was used to get a first insight into the impact the new barrier will have on the on the tidal range in the tidal delta. As well as how much it could potentially impact the reintroduction of the tide to the Haringvliet. The reopening of the Haringvliet would be a part of Delta21's effort to restore some of the local ecological value to the region as a compensation measure for the project. Additionally, the model was also used to determine the effects of the construction of the barrier on the capability for the system to handle high river discharge rates. The findings of the assessment show that the selection of a small tidal opening in the New Haringvliet barrier will significantly negatively impact the capability for the system to discharge high river water, as well as limit the amount of tidal range that will be available in the system. It was determined that constructing the barrier with a tidal opening with an effective cross-section of 10000m2 will provide the best balance between hydrodynamic performance of the system, and barrier construction costs. An analysis of the possible Delta21 construction sequences was used to determine the preferred construction method for the barrier. In this analysis, an economic construction sequence alternative, and an environmental construction sequence alternative were developed, and consecutively evaluated using a multi-criteria analysis. This MCA revealed that the construction of the New Haringvliet barrier using prefab construction elements and techniques was the desired construction method for the project. The results of hydrodynamic and construction sequence assessment, were used as the basis for the barrier's spatial design. The structure was designed with a total of 20 vertical lift gates, each spanning 80m. This would bring the total tidal opening to 10400m2. Vertical lift gates were chosen for the design due to their great reliability and overall cost effectiveness, which are both important considerations for a barrier of this magnitude. On the southern side of the barrier a shipping lock will be the barrier's primary navigational opening. The final phase of the conceptual design focuses on the design of the gated barrier section, and includes the validation of the transport stability of the caisson, the design of the vertical lift gates, and the design of the scour protection and it's filter layers.

The objective of this research is to design and evaluate a new type of rolling gate for the Western lock (Westsluis) in Terneuzen, for which all sensitive and heavily loaded mechanical parts are both easily accessible and located above water. Having all mechanical parts above water not only makes them easier to inspect and maintain, but it also makes them less prone to fouling or obstruction by debris. In this way, the risk of premature gate failure due to failure of wheels/rails is expected to be lower, increasing the overall availability during the lifetime of the lock.
Six variants are designed and evaluated using a qualitative Multi Criteria Analysis (MCA) and the Cantilever rolling gate is evaluated most feasible. The Cantilever rolling gate concept is a system in which all the rolling supports are located on an extension to the side of the gate. The gate is balanced by a counterweight and in a way 'hangs' in the gate chamber. The carriages are connected to the gate by hinges, which ensure the perpendicular horizontal movement of the gate in closed position to seal the lock against rubber profiles on the sill, gate chamber and recess.

Subsequently the Cantilever rolling gate is further elaborated at the case study location by means of structural calculations. The focus of the design calculations is on the load balance of the gate and supports in the longitudinal direction. To minimise the required extension of the gate chamber, the added cantilever length is kept as short as possible. To find the most optimal cantilever length, limits are defined regarding the minimum required force acting downwards on the carriages to maintain equilibrium and the maximum design capacities of the wheels and rails with respect to strength and fatigue.
Based on the performed calculations, the most optimal Cantilever rolling gate design for the Western lock in Terneuzen has the following properties; an added cantilever part with a length of 16.6 meters; a cantilever truss structure constructed of Circular Hollow Sections (69 t); a counterweight directly below the back carriage (1083 t); an 8-wheel front carriage and a 4-wheel back carriage.
The added cantilever structure of 16.6 m extends the gate part of 44.6 m by 37%. The designed cantilever rolling gate fits at the location of the case study, but the lock chamber and rails should be lengthened by 16.6 m to fit the extended gate.
Based on this research it is expected that the concept of a Cantilever rolling gate is technically possible. However, it is not yet certain whether the Cantilever rolling gate will also be feasible in practice. Some additional development is still required before the design can be considered fully technically feasible. For example, it is important that the horizontal force transmission and guidance is further evaluated. It is also recommended to calculate the actual availability and determine whether the difference in availability between the Cantilever rolling gate and the conventional rolling gate outweighs the cost.

According to the European Environment Agency (2016, pp. 137–140) annual mean river flow and the frequency of fluvial floods will have increased by 20% before the year 2100, in North-western Europe. It had been postulated in media in reports (De Ingenieur, 2014; „MIRT-verkenning Grevelingen”, 2012; Slootjes et al., 2010; Slootjes, 2013; Lammers, 2014) that because of this, large pumping stations are required in the Rhine-Meuse delta in the Netherlands. To investigate this postulation, a simulation model in Python was created that describes the Rhine- Meuse delta as four separate water basins with flow exchanges and boundary conditions (astronomical tides and river inflow). From this simulation model it was concluded that every 86–137 years, flood flow rates of the rivers are such, that the design maximum water level is compromised. The acceptable flooding risk is only once every 2.000 years, so this situation is unacceptable. Dutch engineer answered to the postulation and invented a high-capacity pump called the „Deltapump”, with a capacity ranging 170–200 m3s-1. Moreover, a conceptual design for a pumping station was created. After a conceptual design creation, verification calculations and a cost-to-merit evaluation, a pumping station with 28 Deltapumps in total, based on the conceptual design of Schut, was created. This pumping station is integrated within the Haringvlietdam and is covers an area of 420 × 190 m2. Its capacity, dependent on water levels in the Haringvliet, ranges 4.900 to 5.250 m3s-1, making it by an extremely large margin, the biggest pumping station in the world. Its costs, expressed as Net Present Value, are estimated at € 915 million by the year 2100, 70% of which covers the mechanical components of the pumping station and 30% the civil components. After the flood risk analysis and the pumping station design, it was posed that, whilst the pumping station itself has advantages—better capacity per unit width and less costs per unit capacity, it is not a cost-effective method to prevent flooding in the Rhine-Meuse delta. Calculations and the simulation show it only requires operation once every 92 years. It would therefore seem more cost-effective, and a permanent solution, to upgrade all dykes and dams along the Rhine-Meuse delta, so that more water can be stored. This should be investigated in future reports.

This master thesis aims to do a detailed conceptual design of a tunnel to connect the road A15 and A12, which will cross the Pannerdens canal ( represented by red color in figure 1.1) and a deep comparisonwith the bridge plan solution which has already been adopted by the government, which was named ViA15 project.

Summary
In the twentieth century a substantial number of navigation locks were build in the Netherlands. The navigation locks built in that era mostly had a life span of 80 to 100 years. This means that in the coming years most of these locks will be in need of either renovation or replacement. Rijkswaterstaat, the administrator of most of the locks in the Netherlands, is likely to put out tenders for the renovation and replacement of these locks. Companies can subsequently submit a proposal for design and/or construction. This proposal includes a preliminary design of the lock. During this phase of the design multiple possible alternatives will be reviewed to check which of those satisfy the design requirements and how they will be implemented. The time available to create a proposal is limited and the preliminary design phase is time consuming due to the numerous design alternatives available. Therefore, several alternatives are often not elaborated, which already leads to converging in the design process in an early phase. When the time needed to create a design of the alternatives can be reduced, the converging can be postponed to the detailed design and more attention can be paid to out-of-the-box thinking during preliminary design. This time saving can be accomplished by the use of automation and parametric design. With parametric design all the possible alternatives can be calculated in a given range of parameters. After comparison of these generated alternatives a well-educated choice can be made for the direction in preliminary design. This research aims to optimize preliminary lock design in the tendering phase by creating a design-tool that automatically generates all plausible alternatives based on the Design Criteria and boundary conditions of the client.
Eventually, the complete preliminary lock design can be accomplished with a parametric design tool. However, an advantage of a design tool is that it can be composed of different building blocks which all design a specific part of the navigation lock. The basis of the parametric design tool should be a relevant part of the lock when looking at the total costs of this part, the design costs, the variety of options and the relation with other parts. The lock chamber is chosen as a starting point for the design tool. The lock chamber, like the lock head and the mechanics, has high investment costs and a high percentage of design costs. The lock chamber however, is in contrast to the other parts of the lock, not heavily dependent on other components. This makes it an interesting component to make a parametric design tool out of.
The parametric model, that has been developed as a part of this thesis, includes the commonly used chamber types for inland navigation locks. These common types are retaining wall structures with an under water concrete floor including sheet pile, combi and diaphragm walls, and a U-basin structure, which can be constructed in an open building pit or in a temporary retaining wall building pit.
When the design tool is finished, research is conducted on the behaviour of the alternatives in different circumstances. The effects of the main design criteria are examined. These include the length of the chamber, width, depth, water drop and local soil profile. These values are mostly depended on the vessels that need to be accommodated and the local circumstances. Next to that, the impact of different construction methods, the use of materials and the variation in unit prices are elaborated.
In this thesis the second Juliana lock near Gouda is used as reference case. For this case it has been found that a sheet pile wall structure is economically most attractive, followed by the U-basin with an open building pit, a diaphragm wall structure and least feasible a U-basin structure with a retaining wall building pit. It is concluded that the length of the lock does hardly impact the design of the alternatives. The width of the chamber does influence the dimensions of the structure. The floor has to be stronger for larger widths and, because of this, the diaphragm wall structure will become more attractive compared to the U-basin structures. The depth and water drop mainly impacts the dimensions of the walls. This, combined with the increased soil handling with open building pits, leads to decreasing interest in U-basin structures. When looking at the construction methods and materials, it can be noted that the length of the tension piles is especially important for the pile plan and the floor. The concrete strength for the U-basins is of importance, while the under water concrete strength and the casting method hardly influence the total costs.
When looking at environmental impact, the alternative with the least material use is most attractive, the sheet pile wall structure followed, by the diaphragm wall structure. The type of material does heavily influence the environmental impact. The U-basin structures have more environmental impact due to the construction of a larger temporary building pit. The environmental impact consists of three main components, the used materials, transport of these materials and the processes for the construction of the lock. For the U-basin structures the last two components have a large impact, while for the retaining wall structures the materials used have a large footprint.
The proposed CO2 taxes of € 0,05 an €0,20 per kg CO2 equivalent will lead to an average cost increase of respectively 4,5% and 16.5%. The impact per alternative differs, but does not influence the order of economical feasibility. As from a CO2 tax of € 0,68 per kg CO2 equivalent the diaphragm wall structure will become financially more attractive compared to the U-basin structure with open building pit.
Despite the calculated strengths and costs, each structure has its own advantages, disadvantages and limitations in construction, final use and maintenance. Special attention should be paid to these properties, since certain construction methods may be excluded by design requirements and uncertainties can lead to high risk. Further research could focus on steel sheet or combi piles constructed in bentonite excavations, resolving the limitations of vibrations during sheet pile construction and the uncertainties of diaphragm walls.

The goal of this research is to assess technical and economic feasibility of hydropower at the weir-complex of Driel. A local initiative opting to improve the environment gained interest in the idea and asked Arcadis NL for help. The weir complex at Driel lays in a key position in the Dutch river Delta and regulates the flow to the IJssel and Nederrijn, both important parts of the flood protection and important shipping routes. In the Nederrijn 2 other hydro-power plants have been built at weirs. Driel was considered as well, but at the time could not be made feasible due to the low head difference at Driel. Developments in low-head hydro-power have given new possibilities and reason for reassessment. First the location has been analysed, in particular the flow situation. Except for the low head difference, the location lends itself well for a hydroelectric plant. The crux of the research is therefore in making the most of the available head. 4 variants have been worked out: a copy of the downstream hydro-power plant of Maurik as a reference, several variations on low head Kaplan turbines and an Archimedes screw have been assessed. A special variation of the Kaplan is the Venturi enhanced Kaplan, which uses part of the discharge to increase the head difference over the turbine. To estimate the annual production, first a simple approach, assuming a turbine can create a certain head difference, and later a hydraulic model incorporating hydraulic losses and using turbomachinery theory, has been used for the Kaplan design variants. The result of the comparison is that the regular Kaplan variant number 4 with 5 turbines, a combined capacity of 3.160kW and a LCOE of 0,154 € per kWh (using interest rate of 3,3%), has the best economic performance and is therefore recommended for further development. A good second option with a lower initial investment (9,6 million euros versus 20,5 of variant nr. 4) is design variant number 1 with a set of 2 Kaplan turbines having a combined capacity of 1.475kW and a LCOE of 0,161 € per kWh. Despite the regular Kaplan performing better economically, the Venturi Enhanced Kaplan Turbine certainly has potential for low head run of river hydropower and is therefore recommended for further research as well. The increase in power and produced energy gives reason to believe that further optimisation and detailing will lead to a competitive design compared to the regular Kaplan turbines.

The Netherlands has always been in close proximity to water, whether its rivers or the sea. This proximity to water and the need for land to settle and farm, led to vast amounts of land reclamation by constructing dykes along the water features to prevent flooding of the new earned land. This newly reclaimed land started to subside over the years, increasing the difference between the high water in the rivers and the low-lying land even more. With an expanding population, rising water levels and increasingly severe storms, the consequences of a future flood due to a riverine dyke breach are ever rising.
The aim of this thesis follows from these increasing consequences and is to determine the potential structural damage to a masonry house due to a dyke breach leading to a riverine flood.

In the 25 years of existence, the offshore wind market has developed on many aspects. Among others, the dimension of the turbines increased by a factor 15 and the distance to shore increased by a factor of 50. The developments of the offshore wind farms increase the requirements for the installation vessels and as a consequence the present day rates can be up to $300.000. The global potential of the offshore wind market by the year 2030 is forecasted to be 60 GW for Europe and 22GW for the US Atlantic coast. The developments in the market, lead to demands during the construction of offshore wind turbines. The construction phase became more demanding over the years, while the logistical strategy of sailing back and forth to the offshore wind farm with a jack-up vessel, is similar as applied in 1991. The six demands can be fulfilled by performing four required activities at the offshore port. The potential of seven support structures that fulfil the boundary conditions for the offshore port are determined. Important boundary conditions are a maximum vertical load of 12.600 ton, suitability in a water depth range between 30 and 50 meter and a minimum surface area of 17.500 m2. Besides boundary conditions that have to be fulfilled, there are also maximum allowed conditions that determine the workability of a port concept. For a floating port concept the motion response is the leading workability condition. Based on the mobility, motion response and a cost indication, three port concepts are selected. These port concepts are a single barge, a single jack-up barge and a combination of a small jack-up barge and a single barge. The current logistical strategy for construction of an offshore wind farm is compared to various logistical concepts that include an offshore port. The logistical concept with a feeder vessel that sails from the onshore to the offshore port and an installation vessel that sails between the offshore port and the wind farm has the highest potential saving. Taking into account the assumptions made throughout this research, for each executed project by the offshore port the savings are expected to be €23.000.000. These savings consist of a sooner generation of energy and by savings on the construction of an offshore wind farm. The discounted cash flows for the three port concepts shows a potential for the offshore port concept. The net present value of the three offshore port concepts deviates between 52 and 216 million euro. The financial results are most sensitive to the ratio between wind farm capacity and the turbine capacity, also the market share that is interest in applying the offshore port and the day rate of the vessels. When the offshore wind market follows the tendency of developments of the last years, there is a market potential for an offshore port concept to reduce the construction costs. The main recommendations are to analyse the interest of potential port owners, perform a motion response into more detail and validate the financial assumptions.

The Dutch Delta Approach has been set up with the aim of ensuring water safety in the Netherlands and improve it where necessary. The open connection of the Nieuwe Waterweg has become the subject of debate. So far, the Dutch Delta Approach do not take closure of the Nieuwe Waterweg into account. A group of six engineers do anticipate on the closure of the Nieuwe Waterweg and have prepared a scheme for that purpose, called: Plan Sluizen (or Plan Spaargaren). The closure scheme includes provision of navigation locks and a discharge complex. Focus of this report will be on the development of and checking the technical feasibility of the design for a flexible discharge facility in the closure.
At present a part of the river Rhine water is discharged through the Nieuwe Waterweg to the North Sea. Since the water cannot be rerouted, a discharge facility must be included in the closure complex.
First, the Nieuwe Waterweg, as a part of the Rhine-Meuse delta has been analysed and the effects of climate change in this area have been mapped out. Subsequently the report zooms in into the closure, lock and discharge complex that has to be constructed in the future. The two most important requirements are: the closure must be able to withstand the normative water level at sea, including expected sea level rise; the discharge complex must be able to discharge a 20% of the normative Rhine discharge at every random moment.
Looking into the location of the closure and discharge complex went hand in hand with deciding whether to construct one large complex accommodating all components at one location, or to divide the components over two locations. A location for all the components together would be positioned in the Nieuwe Waterweg. When dividing the components of the closure complex, the two locations to be considered are somewhere in respectively the Oude Maas and the Nieuwe Maas, close to the Beneluxtunnel.
A discharge method using Venturi was chosen. Venturi tubes can be used in natural flow conditions, driven by a water head, and improve the efficiency of pumps constructed into the Venturi tube. In future there will be a time when the natural water head has become too small, due to sea level rise, to discharge the required amount of water. The discharge sluice will be changed into a pumping station.
It turns out that 72 pumps are needed with a capacity of 50 m3/s for normative river discharge conditions in 2100. For the normative discharge in 2018 no pumps are needed. For average river discharge, coinciding with storm surges, discharge using the natural water head is possible up to 2100.
The dimensions of the discharge structure were determined. The structure will be adaptable by using different modules in the centre piece of the Venturi tubes.
After determination of the overall dimensions the stability of the structure has been checked. Concrete calculations have been made to check the concrete dimensions of the main parts of the discharge structure.

In the far south of the Netherlands, the erratic river Meuse flows through the landscape. It recently flooded twice in the 1990s, causing much economical damage. Emergency measures, such as a demountable flood wall, were taken to prevent future flooding. And while this solution was to the liking of the inhabitants, the update in the flood safety standard called for a more permanent structure. In the search for an alternative and permanent solution, a glass flood wall was suggested.

Nowadays there are not many examples of glass used in a flood defence in Dutch practice, and certainly not as part of a primary flood defence. It can be classified as an innovation, from which little is known from a structural safety perspective. Glass is used globally to retain water in numerous applications such as aquaria, under water glazing, glass bottom boats, etc; therefore water pressure is not seen as a high risk to the glass. What happens when floating debris hits the glass structure? Impact on glass can result in immediate failure, where the water retaining function could be lost. This thesis aims to answer this question, by theory and later on by impact experiments in a dry setting.

Zeeland, located in the south west of The Netherlands, has suffered major casualties and damage due to the flood in 1953. After the disaster, the Dutch Government appointed the so-called Deltacomittee, provided with the task of advising on the execution of the Deltaplan. As part of the Deltaplan, North Sea estuaries has been closed off from the North Sea in order to provide sufficient safety against flooding in the future.
The 11000 hectare Lake Grevelingen was one of the closed off North Sea estuaries. Two dams and two islands enclose the lake and prevent fresh water flowing in. Characteristic of former estuaries are deep gullies that remain intact as any kind of sediment transport is prevented. Contact with the North Sea is prevented due to the construction of the Brouwersdam, the western border of Lake Grevelingen. Direct after finishing the construction works of the Brouwersdam, Lake Grevelingen showed reducing oxygen gradients and thus a decreasing water quality, especially at the deep gullies. The construction of a stop lock, the Brouwerssluice, was conducted to prevent the further decrease of the oxygen gradient.
Today, more than 40 years after finalizing the Brouwerssluice, the low oxygen gradient tends to rise to shallower areas and reaches critical values. Measures, such as a water inlet system are due to be constructed.
Introducing a tidal range of 50 cm has shown to be a valid solution to overcome the decreasing water quality. The tidal range allows thinking of power generation when water flowing in or out Lake Grevelingen. Generating tidal energy produces revenues and provides renewable energy. Therefore, the design of a Tidal Power Plant in the Brouwersdam has become the goal of this thesis.
Since caissons were used to close Lake Grevelingen off from the North Sea, as a starting point, it has been determined whether these caissons allow reusing with a new function; forming the powerhouse of a Tidal Power Plant. Mainly due to the concrete cover of the caisson, has shown to be inappropriate. Adapting the caissons becomes expensive and very time-consuming.
The starting point of the power plant construction was found in the turbine dimensions. In total six turbine types have been analyzed. Based on their efficiency, fish friendliness and ability to generate power in two directions, two optimal turbine types for low head power generation have been found: free-stream (Tocardo) and a modified bulb turbine (Pentair Fairbanks Nijhuis).
Due to the low head differences between lake Grevelingen and the North Sea, maximum energy generation will be required even for very low head differences. Hence, turbines able to generate energy at such low head differences will be required. In the Preliminary turbine design, two turbine types provided the most promising features: The Pentair Fairbanks modified Bulb turbine and the Tocardo free-stream turbine.
A total cross-sectional discharge area of 960 m2 would lead to a tidal range of 50 cm at Lake Grevelingen. Applying in total 18 turbines in a squared sluiceway with an inner space of 8.24 meter allows introducing a tidal range of 50 cm at the lake.
The free-stream turbine has already proven to generate power in low head environments in previous projects. The PFN modified bulb turbine has not yet been tested on such scale, but due to the expected higher efficiency rate, the energy generation of the PFN lies supposedly much higher than the Tocardo free-stream turbine. Therefore, it has been decided to temporarily apply the free-stream turbine until the PFN turbine has shown to meet the fish friendly requirements while ensuring high efficiencies. With current knowledge, the annual production of the Tocardo and PFN turbine has been estimated at 20 GWh and 80 GWh respectively. The energy production of the freestream turbine is based on the tidal data obtained from 2016. The same tidal data has been applied to the PFN turbine while accounting for the sea level rise as well. Since it is expected the PFN turbine will be in commission at 2030, an estimated sea level rise of 25 cm has been added to the 2016 tidal data.
The thickness of the concrete members in the preliminary design has been set at 500 mm. The conceptual design of structural elements has been dedicated to checking the assumption. In total four base cases have been studied, providing local and global forces emerged from uneven bedding of the rubble foundation layer. The rubble foundation layer functions as a bed protection foundation on which the Tidal Power Plant is located.
The influence of uneven bedding of the rubble foundation bed has been computed by considering the Tidal Power Plant as a beam on an elastic foundation. Due to an uneven bedding, one-dimensional base cases Hogging and Sagging are introduced. Sagging represents a beam on elastic foundation subject to a reduced foundation stiffness at the midsection of the beam. Hogging has been described as the opposite situation of sagging, a reduced bedding stiffness at the beam edges.
The structure’s strength has been determined while applying the hogging and sagging bases cases together with external and local forces. The external forces emerged from the hydraulic pressures in transverse direction and lateral earth pressures in longitudinal direction. The local forces concern the self-weight of an element or locally applied loads, such as the ballast load or road construction. The bending and shear resistance of the concrete members has been checked accordingly.
In addition to the forces obtained from hogging and sagging, a coupled 2-dimensional approach has been applied. Two base cases have been considered in the 2-dimensional plane. The uneven bedding induces the rise of torsional moments in the beam on an elastic foundation. The torsional resistance of the concrete members has been checked. Together with local and global one-dimensional forces, the governing reinforcement ratio has been determined for relevant concrete members. Combining the findings of the one-dimensional approach with the two-dimensional approach has resulted in reinforcement ratios exceeding 3%. Comparing this with the 1 % economical reinforcement ratio value, it has been concluded the 500 mm thickness of the concrete member is insufficient.
In further analyses, it is recommended to provide a cost estimation including revenues made from the energy production. The feasibility of the Tidal Power Plant will be determined by this cost estimation.

Fibre-reinforced polymers (FRPs) are becoming a more commonly used building material in many civil engineering applications including locks. One quality of FRPs is the fact that it has a high strength to weight ratio. By applying FRPs in rolling lock gate design, the self-weight of the gate could be significantly reduced. This in turn could lead to less wear-and-tear to the support carriages, mechanical parts and rails. Self-weight is also an important factor in the stability of a rolling lock gate. A minimum weight is required to counter the moment caused by horizontal loads during opening and closing. If FRPs were to be applied in rolling lock gates an optimization of lightweight versus stability will be required. The objective of this thesis is to investigate the technical feasibility of the FRP rolling lock gate and how the gates design is affected by the stability criteria. Also, the question remains if the FRP design can compete with traditional materials, for example steel.
To quantify the problem a case study was chosen: New Lock Terneuzen. A rolling lock gate is set to be constructed to improve the connection between Ghent-Terneuzen. The rolling gates will be very large, with a span of 55 m and a height of approximately 26 m.
Initially, the rolling gate is designed with a box shape. The global dimensions of the box gate are determined with a hand calculation based on the boundary conditions and design input from the chosen case study. Basic strength, deflection and stability checks are performed. The box gate is dimensioned in both FRP and steel. The following dimensions are found for the FRP box gate: Width of 8.96 m, with retaining plates: skin:280 mm, core: 200 mm and webs: skin: 200 mm, core: 200 mm.
The dimensions found with the hand calculation serve as input for a 3D model of the design. The model is created with Scia Engineer. With this software the gate is checked with finite element analysis. Some additional checks, fatigue and creep, are performed.
The box gate model is adjusted to resemble the gate during movement. This is achieved by changing the supports, leaving the top right corner unsupported. In addition to a 3D stability check of the designed box gate, the width between the supports, representing the carriage width, is varied (from 0.5 to 12 m) and the impact on the stability is evaluated. This impact is quantified by the required dead weight to guarantee stability.
All the results are used to come up with potential improvements or alternatives to the box gate design. The main objective being a gate with increased stability, which is again quantified by the overweight required. A number of ideas are discussed, where optimizing the shape of the gate is explored further.
It is found that the required dead weight to achieve stability increased for all evaluated shapes. The main reason is the distribution of the stabilizing moment, which is split up in a horizontal and vertical component. The shape changes result in an shift from horizontal to vertical, which in turn results in more dead weight required to meet the stability criteria.
The application of FRP in rolling gate design is technically feasible. However from a stability point of view it’s questionable if FRP is the better choice over traditional materials. In the chosen case study, the amount dead weight required to fulfil the stability criteria is significant, and the lightweight quality of FRP cannot be fully taken advantage of. Laminates are designed much thicker when compared to the dimensions required to meet strength and deflection criteria. In other words, material is added primarily for the sake of adding weight.

Reducing the required dead weight was proven to be much harder than anticipated. Even though
a wide base gives a larger arm for the vertical couple, which would lead to a smaller force at an equal moment, the required weight is not necessarily reduced. The applied loads, shape of the gate, location of supports and deflections all affect the distribution of loads over the supports, both horizontal and vertical, of the gate. In a structure of this scale, even small differences can have a significant impact on the stability of the gate and the dead weight required to achieve this stability. The required dead weight to meet the stability criteria must be brought down in order for FRP to be a viable option.

To combat global warming a transition towards renewable energy sources (RES) is essential. Although RES have much lower life-cycle emissions, they do not offer a continuous and fully predictable output like their fossil-fuelled counterparts. Energy storage is paramount in order to include the growing share of these intermittent sources into the grid and provide a reliable supply of energy. In 2016 a long term vision which involves the creation of an artificial island on the Dogger Bank in the North Sea was presented. The island would act as the central spill in an interconnected future economy fuelled by RES. Currently there are no competitive energy storage technologies under consideration that could contribute to this ‘energy hub’. In Europe pumped hydropower storage (PHS) represents over 90% of the grid-connected storage capacity and continues to be identified as the most cost-efficient energy storage technology available today and in the future. Unfortunately, conventional PHS is restricted to mountainous areas and the remaining potential (2291GWh) does not suffice to future demand (estimated at 3596GWh). The plans of developing a large wind farm via the construction of an island made it an attractive base to test the contribution and feasibility of a substitute to conventional PHS: inverse offshore pumped hydropower storage (IOPHS). It relies on the same principles as conventional PHS, only the process is inverted. When the wind farm generates a surplus of energy, the excess power is used to drive hydraulic turbines which pump the water out of the artificially created lake into the surrounding sea. Then when there is a higher demand for energy than the wind farm generates at that time, the sea water is allowed to flow back into the interior lake driving the same turbines. Although the idea of inverse offshore pumped hydropower storage has been around for years, it has never been constructed. The objective of this research is to identify the possible design alternatives and determine how the costs of an offshore pumped hydropower storage facility scale with the power and storage capacity, using existing construction technologies. The construction of the storage plant consists of four main elements: the dam, dredging works, turbines and the turbine housing...