"uuid","repository link","title","author","contributor","publication year","abstract","subject topic","language","publication type","publisher","isbn","issn","patent","patent status","bibliographic note","access restriction","embargo date","faculty","department","research group","programme","project","coordinates"
"uuid:1358b70c-ed09-48c7-b9d2-35b519c9ec4c","http://resolver.tudelft.nl/uuid:1358b70c-ed09-48c7-b9d2-35b519c9ec4c","Probabilistic Design of a Rubble Mound Breakwater","Everts, P.S.","Jonkman, S.N. (mentor); Verhagen, H.J. (mentor); Kuiper, C. (mentor); Bouw, R. (mentor)","2016","All over the world rubble mound breakwaters are built to protect harbours, shorelines, and other vulnerable coastal areas against wave action and currents. Most of the designs for these structures use so called deterministic or semi-probabilistic design methods (level I). With these methods insight in the uncertainties, and consequently the actual failure probability and behaviour of the structure, is lacking. Moreover, less is known about the physical and mathematical relation between the variables and design formulas. The uncertainties in the variables and design formulae in a semi-probabilistic method are taken into account by partial safety factors. This could lead to an overly conservative design. By applying a probabilistic calculation (level II and III) insight is obtained in the relations between variables, the failure behaviour and the probability of failure of the structure. This information can explain why certain structures, which are designed with a semi-probabilistic method, fail even though the design conditions are not reached or in most cases survive above the design conditions. Information on the actual failure behaviour and probability is desired to make a more reliability design and economic optimization. Despite these benefits probabilistic design methods offer, it is not often applied in daily engineering practice. Multiple studies show the feasibility of designing a rubble mound breakwaters with a probabilistic design method in theory. However in practice only few rubble mound breakwaters are designed with a probabilistic design method. This research investigates how a probabilistic design of a rubble mound breakwater can be made in practice and provides some guidelines when a probabilistic design can be considered. The project Taman is used as a case and from this project a rubble mound breakwater is selected for the fully probabilistic calculation. Simplifications are made regarding the applied mathematical models1 and only four failure mechanisms related to the Ultimate Limit State (ULS) are examined. The four main failure mechanisms are: seaside and rear-side armour stability, toe stability and macro stability. With these simplifications a clear and thoroughly insight is gained in the probabilistic design process of a rubble mound breakwater without loosing track of the actual objective of this study. The fully probabilistic calculation is made with a level III probabilistic design method by applying a Monte Carlo simulation. The results show that this method is a good way to take into account the occurring statistical and physical correlation. Furthermore the Monte Carlo analysis gives a good insight in the most dominant failure mechanisms and in the governing failure situations for each mechanism. The results of the fully probabilistic calculation show that making a semi-probabilistic design based on the design rules in The Rock Manual [2007] results in a conservative design (Pf ,sys,tL = 0.5%). One optimization step is made for the simplified case in this research by applying lower stone classes for the four considered failure mechanisms. This results in failure probability (Pf ,sys,tL = 11.25%) which is still lower than the in general allowable probability of failure (Pf ,sys,tL = 15%). Although not all failure mechanisms for the ULS are taken into account, this study proves that a fully probabilistic calculation results in a more optimized design compared to a semi-probabilistic design method for the examined case. In conclusion a fully probabilistic calculation for a rubble mound breakwater is possible in practise. The results show that it is certainly beneficial to apply a fully probabilistic calculation (Level III) compared to a semi-probabilistic (level I) calculation. However, not in all cases it is possible to apply a fully probabilistic calculation and a couple of aspects should be checked before starting the calculation: • Statistical and physical correlation of the main variables have to be known • Sufficient reliable data for boundary conditions should be available • Applied mathematical models should be incorporated in the fully probabilistic calculation • Design requirements don’t follow directly from the standards and therefore must be agreed with the client This research shows that neglecting the statistical and part of the physical correlation results in an over dimensioned design for a rubble mound breakwater. A fully probabilistic (level III) design method with a Monte Carlo simulation proves to be a good way to include these correlations in the fully probabilistic design process. Sufficient reliable data for the boundary conditions should be available at the project location to make a fully probabilistic design method feasible. Large uncertainties in the boundary conditions result in a high failure probability of the rubble mound breakwater. To determine for which boundary conditions sufficient reliable data has to be known, a FORM analysis (level II) could be applied. This analysis gives ®-values which indicates the influence of each input variable on the failure probability of the rubble mound breakwater. For example in the examined case the uncertainties in the significant wave height have a large contribution to the variation in the probability of failure. The results show that a fully probabilistic calculation is not feasible in this case when the uncertainties in Hs have a standard deviation (σ) of 25% or more. In the semi-probabilistic design the hydraulic boundary conditions are determined via the models SWAN and Delft3D. Additionally the model D-Geo Stability is used for the semi-probabilistic design to check the geotechnical failure mechanisms. In this research is concluded that all hydraulic, geotechnical and geometric conditions need to be carried out in fully probabilistic way. For the fully probabilistic calculation of the simplified case simplifications are made for the mathematical models. These simplifications give a good approximation of the models in this study. However, the mathematical models have to be (in some way) integrated in the statistical analysis to make a fully probabilistic design.","probabilistic design; correlation; rubble mound breakwater","en","master thesis","","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:7f4a8b7d-e00e-4818-8340-be1d3284b857","http://resolver.tudelft.nl/uuid:7f4a8b7d-e00e-4818-8340-be1d3284b857","Design and reliability evaluation of a glass flood defence","Kentrop, J.","Jonkman, S.N. (mentor); Voorendt, M.Z. (mentor); Nijsse, R. (mentor); Lassing-van der Spek, B.L. (mentor)","2016","Typical for the Dutch landscape are the many polders, which are situated below sea level and below waters directly surrounding the polders. A visual separation between land and water is caused by the flood defences that protect the polders from flooding. In 2005, artist Paul Izeboud came with the idea to make a transparent flood defence, thereby making it possible to experience land and water simultaneously, without standing on top of the dike. In 2011, Eduard Böthlingk worked out this idea in an architectural design of ‘The glass dike’. Böthlingk is planning to realize the glass dike inside a regional flood defence that protects the Duifpolder (in the province of South-Holland) from flooding. Based on the architectural design, an engineering design of the glass dike is made in this thesis. This design should satisfy reliability requirements from the Flood Safety Standard. For the regional flood defence that is surrounding the Duifpolder, this safety standard prescribes a design water level with an exceedance probability of 1 in 100 years. The glass dike should be able to safely withstand this water level. Apart from the Flood Safety Standard, reliability requirements that follow from the Eurocode should be satisfied as well. For conventional parts of the structure (foundation, concrete elements, etcetera), design checks were performed with a semi-probabilistic method. For this, partial factors from Eurocode Reliability Class 2 were applied. For the glass elements, a full probabilistic method was applied to compute the failure probability due to overloading. Furthermore, threats to the glass were identified. The most important threats are impact due to a boat collision, fire and explosions. Measures to prevent these incidents and/or to reduce consequences were proposed. Glass is an unpredictable material with respect to its structural behaviour. Its strength is still subject of many researches. It is recommended to also investigate its resistance against fire. Although glass is a vulnerable structural material, it was found that, in general, realization of a glass flood defence is technically feasible.","glass dike; glass flood defence; probabilistic design; semi-probabilistic design; structural glass","en","master thesis","","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:8d5830d8-21e1-479b-a922-3dc4bb18527a","http://resolver.tudelft.nl/uuid:8d5830d8-21e1-479b-a922-3dc4bb18527a","Probabilistic design of the renovation of the Afsluitdijk","Veraart, C.G.D.M.","Kok, M. (mentor); Schweckendiek, T. (mentor); Verhagen, H.J. (mentor); Ravenstijn, P. (mentor); Regeling, H.J. (mentor)","2014","","flood risk; Afsluitdijk; probabilistic design","en","master thesis","","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","Flood Risk","",""
"uuid:2e2e6048-1578-460a-961a-ae6d0bfadbb7","http://resolver.tudelft.nl/uuid:2e2e6048-1578-460a-961a-ae6d0bfadbb7","Probabilistic Design of Relief Wells as Piping Mitigation Measure","Miranda, C.A.","Kok, M. (mentor); Schweckendiek, T. (mentor); Huber, M. (mentor); Arnold, P. (mentor)","2014","The traditional Dutch way to deal with piping for river levees is the implementation of piping berms. The disadvantage of such a measure is the inland space required, especially in urban areas. Relief wells, on the other hand, require less or no inland space and therefore represent an attractive solution as mitigation measure against piping. The aims of this research are first, to show how reliability analysis of relief wells systems can be carried out, and second to examine the costs required to achieve a reliability target for piping failure, as set in the Netherlands. The outcomes of this analysis will help comparing relief wells with piping berms in economic terms. To obtain these results, the statistical parameters of the influencing variables are studied using both, the collected data from existing projects in the Netherlands, and data from relevant literature. A reliability-based design approach is followed to estimate the reliability of relief wells systems. In order to establish the limit state functions, the assessment methods recommended by the Dutch flood defence regulations are used. Applying the probabilistic axioms it is possible to resemble piping failure as a parallel system assessing uplift and heave failure mechanisms. To estimate the hydraulic head in relief wells system, the United States Corps of Engineers method is applied, as well as the latest developments in flood risk analysis, achieved by the VNK project, which are used to determine the reliability target. To estimate the probability of failure and the system reliability, MCS and FORM methods are utilized. A tailor-made comprehensive tool is built in Matlab to compute the hydraulic head in relief wells system and to perform the probabilistic analysis. Subsequently, a LLC analysis is performed with the aim to account for the life cycle of relief wells. A comparison of the net present value of the two alternatives (relief wells and piping berms) is made. Finally, analysis of two case studies with different scenarios are performed to show the possible economic advantages of installing relief wells and sensitivity analysis is used to underpin the robustness of the conclusions. The results show that, using USACE method, the blanket and the aquifer permeability, as well as the hydraulic losses, are the dominant variables (from the 'load' side). The sensitivity factors show high discrepancy between partially and fully penetrated wells. Even when the entrance losses cannot be accurately predicted, a total clogging scenario of the filter can be neglected. One main limitation for the applicability of relief wells system, is that there is a maximum achievable head reduction. This maximum head reduction is limited to the minimum possible well spacing (a>D/4). Results from the case studies show that relief wells are a cost-effective as piping mitigation measure, outperforming piping berms. This advantage can be up to a factor of ten regarding initial investment. This allows accounting for a shorter life cycle for relief wells in order to equate the same LCC as piping berms.","reliability; piping berms; piping; probabilistic design; relief wells; life cycle cost","en","master thesis","","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","Hydraulic Structures and Flood Risk","",""
"uuid:ce8d7ee3-6ffb-4858-b663-549e09f79249","http://resolver.tudelft.nl/uuid:ce8d7ee3-6ffb-4858-b663-549e09f79249","Multifunctional Flood Defences: Reliability Analysis of a Structure Inside the Dike","Van Mechelen, J.","Jonkman, S.N. (mentor); Molenaar, W.F. (mentor); Terwel, K.C. (mentor); Van Meurs, G. (mentor)","2013","Multifunctional use of the flood defences is as old as the flood defences themselves. Historically infrastructure, housing and livestock are located on the flood defences. Over the years, the cities along the rivers became bigger and bigger. With the still increasing demand for spatial development it is inevitable to also start combining other functions with the flood defences. The underground space of the flood defences is not yet used. Constructing a structure inside a dike is a solution to create more space. With multifunctional use of the flood defences are a lot of different parties involved with each its own interest and purposes. This results in a difficult and devious design process. The technical difficulties are researched in the master thesis in order to optimise this design process. The Dutch guidelines for flood defences as well as the Eurocodes are relevant for the design of multifunctional flood defences. Dealing with the hydraulic loads on the structure leads to uncertainties for the reliability of the flood defence. Applying partial factors on forces resulting from design water level with already a very small exceedance probability seems to introduce excessive amount of reliability into the calculations. A case study is performed to research the issues during the design process of a multifunctional flood defence. The Grebbedijk is chosen as location for the case study because of the demand for spatial development as well as the demand for flood safety. The Grebbedijk is a relatively small dike protecting a relatively large area with a high economic value. The Grebbedijk is often named as a possible first Delta dike. Together with the demand for parking close to the city centre of Wageningen, this location meets both criteria for a multifunctional flood defence. The assessment of the design made for the Grebbedijk confirmed the idea that the forces resulting from the water level are treated in a too conservative way by applying partial factors over design water levels with already small exceedance probabilities. This effect is obtained in the calculations for the failure mechanisms overall stability and structural strength. In order to analyse the reliability of the multifunctional flood defence, first order reliability method (FORM) analyses are carried out. Three failure mechanisms are considered: horizontal stability, overturning stability and strength of the wall. The failure probability of each failure mechanism is calculated. All three failure mechanisms have a lower failure probability than the required failure probability. The partial factors used in the semi probabilistic approach are calibrated in order to find the correct partial factors. The calibrated partial factors for the force related to the water level showed a variation equal to the proportionality of the force to the water level. The partial factors are in this case not useful. The exceedance probabilities of the design water levels resulting from the FORM analyses are very similar and in the same order as the failure probabilities. This resulted in the conclusion that using a design water level with an exceedance probability equal to the failure probability introduces enough reliability into the calculations. The partial factors for the forces not related to the water level were all very close to one. Resulting in the conclusions that using partial factors of 1.1 for unfavourable force and 0.9 for favourable force, would be sufficient to obtain the target failure probability. The applicability of these partial factors is not unlimited. The water level is the most important parameter in these calculations. Other forces might become more important in other cases. Further research has to be carried out to say something about the extent to which the partial factors are applicable.","multifunctional flood defences; probabilistic design; reliability analysis; FORM analysis; partial factors","en","master thesis","","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","Hydraulic Engineering","",""
"uuid:26dfbbe9-9400-4b2c-9072-5635b5e0d6d4","http://resolver.tudelft.nl/uuid:26dfbbe9-9400-4b2c-9072-5635b5e0d6d4","Berthing loads in structural design: Validation of partial factors","Versteegt, G.","Vellinga, T. (mentor)","2013","Structural design of these marine facilities is not implicitly covered in EN1990 (European Norm), and the types of loads and load combinations that are to be considered are different from those for buildings and bridges, since they concern operational loadings from vessels berthing and mooring, and also loads from vessels moored acting indirectly through mooring lines and fenders. The overall objective is to find and recommend action and combination factors for the safe and cost-effective structural design of marine facilities using the deterministic limit-state design methodology of EN1990.","partial factor; Monte Carlo; characteristic action; berthing loads; probabilistic design","en","master thesis","","","","","","","","2014-05-09","Civil Engineering and Geosciences","Hydraulic Engineering","","Hydraulic Engineering","",""
"uuid:ad0a5aaa-9493-4ed0-a02e-1c0a2d2c6156","http://resolver.tudelft.nl/uuid:ad0a5aaa-9493-4ed0-a02e-1c0a2d2c6156","Effectiveness of sensors in flood defences","Spaargaren, T.N.","Vrijling, J.K. (mentor); Kok, M. (mentor); Van der Meer, M.T. (mentor); Wojciechowska, K. (mentor)","2012","Introduction The popularity of monitoring dikes with sensor techniques is rising. It is claimed that sensor techniques lead to significant cost savings and can predict an upcoming dike collapse. But a technical foundation to use the sensor monitoring information in flood safety assessment is lacking. This research investigates the contribution of sensor monitoring information to flood safety and the cost-effectiveness of sensor monitoring. Sensor techniques have been tested in full-scale dike failure experiments at the IJkdijk, trying to predict an upcoming dike collapse. The sensor techniques are capable of monitoring deformation, temperature, water pressure, vibrations and moisture. The state of the sensor techniques is doubtful due to subjective analyses, controlled test conditions and a wide variety in failure prediction times: from 1,5 to 102 hours. Implementation of sensor information Water pressure is the only variable that constitutes an input for dike safety assessment models. Monitoring water pressures affects the epistemic uncertainty of the water pressure schematization which is caused by the translation from the hydraulic load to water pressures. One must be aware that sensor monitoring either leads to an increased assessment of flood safety if the prior schematization turns out to be done conservatively or a decrease in flood safety if the prior schematization turns out too optimistic. One would expect an increased assessed flood safety due the intended conservative approach. But prior schematization mistakes imply a decreased assessed flood safety. Moreover, monitoring water pressures has minimum impact on the flood safety assessment if other uncertainty aspects dominate the stability assessment. A case study of the canal of Nauerna denotes that the water pressure has resulted in a higher assessed flood safety, but the uncertainties regarding the soil conditions dominate the stability assessment. However, sensor monitoring on itself does not affect the real flood safety: only physical measures affect the real risk of flooding. Important information is obtained from monitoring high water events such that water pressure models can be calibrated to determine design loading conditions for the periodic safety assessment. Also, an additional application is to identify unforeseen risks. Cost-benefit analysis Conceptual cost-benefit models have been set up to determine the cost-effectiveness of sensor monitoring over the long-term. The monitoring costs consist of installation, maintenance and operational costs. The benefit from permanent dike reinforcements is gained from specifying the long-term optimal investment strategy based on the minimum sum of flood risk and reinforcements costs. The monitoring information from relevant high water events affects the assessed flooding probability. If the sensor monitoring reduces the assessed flooding probability, the assessed flood risk lowers and savings on permanent dike reinforcements. If a higher flooding probability is obtained by sensor monitoring, this financially leads to additional investments and negative benefits. But the value of knowing this higher flood risk is rationally beneficial. The benefit from temporary measures is gained from timely execution of emergency measures based on the early warning of the sensor system. This benefit depends on the prediction time of the sensor monitoring system and the reaction time to execute the emergency measure. Additional costs for executing the emergency measure must be incorporated. The cost-benefit models have been worked out in case studies for dike-ring 48 and 14. Conclusion The conclusion of this research is that sensor monitoring can be implemented in the flood safety, by specifying dike reinforcements in both the periodic safety assessment, as well as the operational situation. However, the investments in sensor monitoring have to be made while a long waiting time is expected before benefits turn out. Then these benefits can financially be disappointing, but do have a certain value of information.","sensor monitoring; cost-benefit analysis; macro instability; flood risk; probabilistic design; flood defence","en","master thesis","","","","","","","","2012-11-09","Civil Engineering and Geosciences","Hydraulic Engineering","","Hydraulic Structures & Flood Risk","",""
"uuid:40b00124-78d2-41b0-9465-6f1ceb8c9292","http://resolver.tudelft.nl/uuid:40b00124-78d2-41b0-9465-6f1ceb8c9292","A probabilistic design of a dike along the Senegal River","Henny, A.F.","Vrijling, J.K. (mentor); Van Gelder, P.H.A.J.M. (mentor); Hoes, O.A.C. (mentor); Tonneijck, M.R. (mentor)","2012","","probabilistic design; dike; Senegal River; water level; extreme values","en","master thesis","","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","Hydraulic Engineering","",""
"uuid:b704a5d0-e464-4410-83ba-d369c8a0cff9","http://resolver.tudelft.nl/uuid:b704a5d0-e464-4410-83ba-d369c8a0cff9","Risk-based control of external salt water intrusion for the Rhine-Meuse Estuary","Zethof, M.","Stive, M.J.F. (mentor); Jonkman, S.N. (mentor); Van Overloop, P.J.A.T.M. (mentor); Van Vuren, B.G. (mentor); Van Beek, E. (mentor); Beijk, V.A.W. (mentor)","2011","The fresh water supply will be more under pressure, due to the predicted effects of climate change in the Netherlands. More frequent salt water intrusion during the summer semester is caused by the joint occurrence of low river discharges and the expected sea level rise. The control of external salinity is necessary to guarantee a sufficient water quality of the main water system and so protect the fresh water inlets from the intruding saline water. Consequently, regional water systems are able to take in fresh water of the main water system to control internal salinity, through counteracting salt seepage by means of salt ?ushing. The control of external salinity can be realized by the implementation of measures that interfere in the main water system; e.g. by optimizing the fresh water distribution. Whether a measure will be implemented depends on the decision-making process. This study is initiated, because of the arisen discussions about the pursued fresh water policy for the drought in 2003. Salinity risk management aims to assess the cost-effectiveness of measures that focus on the fresh water supply, by means of evaluating the costs and the bene?ts of a measure. This study investigates the possibilities of the implementation of a risk-based approach within the present Dutch fresh water policy, which is nowadays based on a deterministic approach. A salinity risk management model is developed that basically is composed of three phases that research the following questions; i.e. 1.) How does the system of external salt water intrusion in the Rhine-Meuse Estuary function for given scenarios? 2.) What is the frequency of occurrence of external salinity? Given that external salinity occurs, what are the consequences? What is the resulting salinity risk? 3.) Is the established risk acceptable? If not, which alternative measures are able to reduce the present risk level? The developed research model is examined in a case study for the risk evaluation of external salt water intrusion in the Hollandse IJssel, in particular the fresh water inlet of Gouda that provides fresh water to the control area of Rijnland. This study concludes that a risk-based approach is implementable in the Dutch fresh water policy, but extended research is necessary to obtain more reliable exceedance frequencies of a Chloride concentration. This study developed two probabilistic models; i.e. for tide-dominated locations and river-dominated locations. A third type probabilistic model should be developed for locations that are not tide- or river-dominated. Secondly, more precise statistical analysis should be conducted after the discharge variation in course of time for low river discharges. Besides, statistical research is recommended after the variation of the probability distributions thorough the summer semester of low river discharges, high sea water level set-ups and a precipitation de?cit.","risk assessment; drought; salinity; damage assessment; probabilistic design; risk reduction; verzilting; Rijn-Maasmonding; Hollandse IJssel; Rijnland Gouda; climate change; fresh water policy","en","master thesis","","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","Coastal Engineering","",""
"uuid:0fe4643f-d868-4849-90af-579fb543a8b2","http://resolver.tudelft.nl/uuid:0fe4643f-d868-4849-90af-579fb543a8b2","Probabilistic design of settling basins for environmental compliance: Development and evaluation of a risk-based approach","De Lange, W.","Vrijling, J.K. (mentor); De Boer, G.J. (mentor); Van Gelder, P.H.A.J.M. (mentor); Den Heijer, C. (mentor); Van Koningsveld, M. (mentor); Wang, Z.B. (mentor)","2011","The environmental impacts caused by suspended sediments are an important issue in the environmental impact assessment (EIA) of dredging and reclamation projects. This thesis is restricted to provide insight into the emission of suspended sediment particles due to the release of return water. This water is used to pump dredged material to the disposal area after which the excess water is released. Settling basins can be used to remove fines particles from the return water. The remaining concentration of suspended particles (outflow concentration) is hard to predict due to varying circumstances (e.g. wind, discharge and inflow concentration) and uncertainties in the settling process (e.g. agglomeration of clay particles). A probabilistic approach is a powerful method to incorporate these uncertainties. A probabilistic approach requires an efficient model that takes into account the relevant physical processes in a simplified way. A model is developed to simulated the transport of suspended sediment in the two dimensional vertical plane. Besides the turbulent mixing, processes as flocculation (agglomeration of clay particles) and secondary flow are included. This enables the model to provide realistic predictions of the concentration of suspended sediment in the vertical plane. The model is compared with measurement data and existing solutions which gives promising results. A probabilistic analysis of a case study provides insight into the main sources of uncertainty in the outflow concentration. Wind has a significant impact on the outflow concentration due to turbulent mixing and secondary flows. Furthermore, processes related to the clay particles (minimal settling velocity and flocculation) are very decisive. These parameters are proposed as calibration parameters. There appears to be an optimal basin depth. When the basin is deeper than this optimal basin depth, the positive effect of the longer residence time is eliminated by the larger turbulent mixing that is caused by the increased depth. By expressing the environmental risk of the contractor in a financial risk (fine or downtime), it is possible to determine an economic optimal design of a settling basin. This economic optimum is determined for both the basin depth and the discharge (the latter can be considered as the choice of equipment). The optimal choice of equipment is between the minimal production costs at an acceptable risk. For this risk, time effects and the time period over which the risk can be spread, play an important role. Finally, the profitability of wind protection for settling basins is investigated. This appears to be beneficial for the case study. The availability of a probabilistic model for determining the outflow concentration of settling basins offers interesting possibilities for a probabilistic analysis of environmental impacts of dredging and reclamation projects. This is because not only emissions are quantified but also insight is provided into the uncertainties and the sources of these uncertainties. This also enables the determination of an economically optimal design of a settling basin and provides insight in the associated financial risks.","environment; settling basins; probabilistic design; suspended sediment; return water","en","master thesis","","","","","","","","2013-04-08","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:0a18f9e9-2d3a-4504-bfe3-549025fa8272","http://resolver.tudelft.nl/uuid:0a18f9e9-2d3a-4504-bfe3-549025fa8272","Economic optimal design of the Maasvlakte 2","Segers, J.P.T.","Vrijling, J.K. (mentor); Voortman, H.G. (mentor); Vrouwenvelder, A.W.C.M. (mentor); Stroeve, F.M. (mentor)","2001","Advanced plans were made by the Dutch government to extend the port of Rotterdam by means of the construction of a land reclamation in the North Sea, the Maasvlakte 2. Because no safety standards exist for the Maasvlakte 2, it is useful to determine an optimal design from an economic point of view by cost-benefit analysis. The economic optimal design of the Maasvlakte 2 is assumed to be the design for which the net present value (NPV) of the total costs (including loss of benefits) is minimal. An accompanying optimal level of safety for the Maasvlakte 2 is also found. In this analysis, the Maasvlakte 2 is assumed to be a system composed of three elements, a breakwater, a sea defence and a terrain area. For each element, decision variables are selected which have influence on the resistance (strength) and the costs and benefits of the Maasvlakte 2, and also represent relations between elements. For the breakwater, the crest height and the diameter of the concrete blocks in the armour layer are considered as decision variables. For the terrain area, the height of the terrain area is the only decision variable considered. For the sea defence, the crest height, the diameter of the quarry stones in the protection layer of the outer slope and the angle of the outer slope are considered as decision variables. A selection of failure modes is also made for each element.Each failure mode is written in the form of a reliability function Z = R-S in which R is the resistance and S is the sollicitation. For the failure modes, hydraulic conditions (waves, water levels) represent the sollicitation. The geometry and strength of the elements, also determined by the decision variables, represent the resistance. In the calculation of the economic optimal design of the Maasvlakte 2, a bottom-up approach is used: 1. at first, calculations are executed for each failure mode 2. then, these results are used in the optimisation per element 3. finally, optimal element results are used in the optimisation of the system. This way the optimal design for Maasvlakte 2 is derived. With this optimisation method, a probabilistic design is determined and compared with a deterministic design it proves to be much more cost effective.","probabilistic design; optimisation","en","master thesis","","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:32a766f7-8daf-4fe0-a79d-0a5f1177fd45","http://resolver.tudelft.nl/uuid:32a766f7-8daf-4fe0-a79d-0a5f1177fd45","Probabilistische levensduurberekening van het sluizencomplex Vlissingen","Wehrung, M.J.","Vrijling, J.K. (mentor); Bijen, J.M.J.M. (mentor); Bakker, K.J. (mentor); Zitman, T.J. (mentor); Teunissen, E.A.H. (mentor)","2001","Het sluizencomplex Vlissingen is opgebouwd uit stalen damwandconstructies. In de afgelopen 45 jaar is er minimaal onderhoud gepleegd aan deze constructies. De provincie Zeeland was benieuwd naar de huidige staat en de te verwachten restlevensduur van het complex. Witteveen+Bos heeft vervolgens een uitgebreid onderzoek uitgevoerd, waarbij een groot aantal metingen van staaldiktes en waterstanden zijn gedaan. Met de verworven datasets is de restlevensduur bepaald. Aanleiding voor dit afstudeeronderzoek is de vraag of het mogelijk is met dezelfde gegevens een volledig probabilistische berekening te maken en of een dergelijke berekening zal leiden tot andere inzichten in de restlevensduur. Op basis van de staaldiktemetingen is een, fysisch verklaarbare, corrosiezonering opgesteld. Aangenomen is dat er in iedere zone een homogeen, gelijkmatig corrosieproces optreedt met een natuurlijke spreiding. De mate van spreiding is gebaseerd op de metingen. Bepalend voor de grootte van het buigend moment zijn vooral de grondparameters phi en c, het bodemniveau voor de wand en de waterstandsverschillen. De onzekerheid omtrent de waarde van deze parameters is in de berekening meegenomen als een spreiding rond het buigend moment. In dit afstudeeronderzoek zijn twee modellen opgesteld. Het eerste model berekent per jaar de kans dat de wand bezwijkt door toedoen van het buigend moment. Het model verondersteld een lineaire afname van de staaldikte als gevolg van corrosie, maar bovendien een Iineaire toename van de mate van onzekerheid omtrent de corrosie. Het buigend moment wordt opgenomen door een systeem van samenwerkende damwandprofielen. Het tweede model berekent per jaar de kans op verlies van de kerende functie door het ontstaan van gaten in de wand. Het model verondersteld een constante groei van een corrosieput. De verdeling van de maximale corrosie wordt benaderd met een extreme waarde verdeling voor maxima van de gelijkmatige corrosie. Conclusie is dat een probabilistische berekening mogelijk is en dat de resultaten duidelijk afwijken van een traditionele berekening. Nader onderzoek zou zich moeten richten op het aantal meewerkende damwandprofielen, de correlatieafstand van corrosie en het verdisconteren van reeds bewezen sterkte in de rekenwaarde van de grondparameters.","locks; probabilistic design; risk analysis","nl","master thesis","","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:0ee772fa-2052-4190-9a3c-ffe3730bcd19","http://resolver.tudelft.nl/uuid:0ee772fa-2052-4190-9a3c-ffe3730bcd19","Probabilistisch Ontwerpen van Verticale Golfbrekers","Haile, A.","Vrijling, J.K. (mentor); De Groot, M. (mentor); Meermans, W. (mentor)","1996","De steeds groter wordende diepgang van zeeschepen vereist dat golfbrekers op grotere dieptes aangelegd moeten worden. De kosten van stortsteen golfbrekers op grote dieptes zijn aanzienlijk hoger dan op kleine dieptes. Verticale golfbrekers lijken een betere alternatief te zijn met betrekking tot de totale kosten prestatie, standaardisatie, kwaliteitscontrole, milieu aspecten, uitvoering en onderhoud. Vanwege het stochastische karakter van golfbelasting en sterkte-eigenschappen lijkt een probabilistische ontwerpmethode de beste oplossing voor stabüiteitsproblemen van verticale golfbrekers te zijn. Bezwijkmechanismen van verticale golfbrekers zijn met probabilistische ontwerpmethoden onderzocht. Voor dit doel is een verticale golfbreker, geplaatst boven een vrij hoge stortsteenfundertng bekeken. Na een opsomming van de belangrijkste bezwijkmechanismen te hebben gemaakt, zijn enkele bezwijkmechanismen verder uitgewerkt. Probabilistische berekeningen zijn zowel op niveau II (Approximate Full Distribution Approach) als op niveau III (Monte Carlo) gemaakt. De resultaten van beide methoden zijn met elkaar vergeleken door voor een aantal caissonbreedtes de faalkans te bepalen en in een grafiek uit te zetten. Ten slotte is gekeken naar de faalkans van het totale systeem dat bestaat uit de onderzochte bezwijkmechanismen. Uit de berekeningsresultaten blijkt dat van de onderzochte bezwijkmechanismen, het landwaarts afschuiven van de ondergrond het grootste bezwijkgevaar oplevert. Het zeewaarts afschuiven van de ondergrond (d.w.z. bij een golfdal) heeft daarentegen een zo kleine faalkans dat die verwaarloosd kan worden. Uit de niveau II berekeningen is gebleken dat bij alle mechanismen de variantie van de significante golfhoogte de grootste bijdrage heeft in de variantie van de betrouwbaarheidsfunctie van elk mechanisme. Vergelijking van de resultaten van berekeningen op niveau II en Monte Carlo simulaties laat zien dat de twee methoden niet altijd vergelijkbare resultaten geven. De reden dat een niveau II berekening voor sommige bezwijkmechanismen faalkansen levert die afwijkend zijn van faalkansen uit een Monte Carlo simulatie zou in de niet lineariteit van de betrouwbaarheidsfuncties kunnen liggen. Voor een verder onderzoek wordt aanbevolen om ook via een volledige integratie, per bezwijkmechanisme, het verloop van de faalkans als functie van de caissonbreedte te bepalen en met de niveau II en Monte Carlo resultaten te vergelijken.","breakwaters; probabilistic design; havendam","nl","master thesis","","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""
"uuid:d077b5f7-6ef4-4f51-8577-467877dbcf77","http://resolver.tudelft.nl/uuid:d077b5f7-6ef4-4f51-8577-467877dbcf77","Probabilistic design of breakwaters, the Ennore breakawater project: Failure mechanisms of a crested rubble mound breakwater","Plate, S.","Kalff, F.R. (mentor); Meermans, W. (mentor); Vrijling, J.K. (mentor); D' Angremond, K. (mentor)","1995","Breakwaters differ from each other by their functions or their type. The most important function of breakwaters is to allow the ships to be loaded and unloaded in calm water conditions and to provide dock or quay facilities. Several types of breakwaters can be distinguished, depending on their operation and design. The most common breakwater concepts are divided into two types: statically stable and dynamically stable breakwaters. The site variables, set by the situation at Ennore, concerne the geotechnical aspects, the construction material and the hydraulic boundary conditions. The hydraulic boundary conditions will be determined by the wave climate during extreme weather conditions, which is during cyclones. Cyclones arrive on the east coast of India usually with a return period of 2 years. Wave motions in harbours can, under extreme conditions, endanger the handling of vessels at berth. Therefore a certain degree of tranquillity of the harbour basin is required. The tranquillity of the harbour basin is essential for ships to load and unload in calm water conditions. Too high waves in the harbour basin will cause an unsafe handling of ships. Should the coal handling cease at Ennore, then the storage of coal will run out, leading to the breakdown of the power station. The breakwater structure has to reduce the wave heights in the harbour by adequate layouts. By analysing the failure mechanisms of all the different parts of the breakwater, reliability functions can be formed and the probability of failure, according to the various mechanisms, can be calculated. These reliability functions, described by each failure mechanism, are mainly based on hydraulic and geotechnical parameters. This study attempts to survey all imaginable failure mechanisms that may occur during the design, construction, and lifetime of the crested rubble mound breakwater at Ennore. In order to address the problems encountered systematically, a general faulttree has been given. The quantification of some failure mechanisms for the crested rubble mound breakwater at Ennore is effected for the following failure mechanisms: - instability of a rock armour slope - instability of an armour layer with ACCROPODE elements - slip circle of a rock armour layer - horizontal displacement of the crest element. The quantification of these failure mechanisms is a complex task which most important difficulty resides in the determination of the mean value and the standard deviation of the variables. After the calculation, an adjustment of these values may take place in order to improve the design.","breakwaters; India; probabilistic design; ha;rbour mole","en","master thesis","","","","","","","","","Civil Engineering and Geosciences","Hydraulic Engineering","","","",""