The Experts below are selected from a list of 174 Experts worldwide ranked by ideXlab platform
Corrado Altomare - One of the best experts on this subject based on the ideXlab platform.
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Influence of Convex and Concave Curvatures in a Coastal Dike Line on Wave Run-up
Water, 2019Co-Authors: Suba Periyal Subramaniam, Corrado Altomare, Babette Scheres, Malte Schilling, Sven Liebisch, Nils B. Kerpen, Torstern Schlurmann, Holger SchüttrumpfAbstract:Due to climatic change and the increased usage of Coastal areas, there is an increasing risk of Dike failures along the coasts worldwide. Wave run-up plays a key role in the planning and design of a Coastal structure. Coastal engineers use empirical equations for the determination of wave run-up. These formulae generally include the influence of various hydraulic, geometrical and structural parameters, but neglect the effect of the curvature of Coastal Dikes on wave run-up and overtopping. The scope of this research is to find the effects of the Dike curvature on wave run-up for regular wave attack by employing numerical model studies for various Dike-opening angles and comparing it with physical model test results. A numerical simulation is carried out using DualSPHysics, a mesh-less model and OpenFOAM, a mesh-based model. A new influence factor is introduced to determine the influence of curvature along a Dike line. For convexly curved Dikes (αd = 210° to 270°) under perpendicular wave attack, a higher wave run-up was observed for larger opening angles at the center of curvature whereas for concavely curved Dikes (αd = 90° to 150°) under perpendicular wave attack, wave run-up increases at the center of curvature as the opening angle decreases. This research aims to contribute a more precise analysis and understanding the influence of the curvature in a Dike line and thus ensuring a higher level of protection in the future development of Coastal structures.
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Vulnerability of Buildings on Coastal Dikes due to Wave Overtopping
Water, 2017Co-Authors: Xuexue Chen, Sebastiaan N. Jonkman, Sander Pasterkamp, Tomohiro Suzuki, Corrado AltomareAbstract:The vulnerability of buildings on Coastal Dikes due to overtopping wave impacts is difficult to assess. A method is developed in this paper to quantify the vulnerability of masonry buildings on a Coastal Dike exposed to wave overtopping. Using previous studies, the accidental loads due to the extreme wave impacts are characterized. Using the approach from Eurocode 6, the strength of masonry buildings under these loads is assessed. Results from a case study in Belgium show that masonry buildings located 10–15 m away from the seafront would suffer from localized damage, such as windows being broken under a 1000 year storm. The building would collapse under a 10,000-year storm. The method can be used to assess the safety of existing buildings on Coastal Dikes and to design new buildings.
Holger Schüttrumpf - One of the best experts on this subject based on the ideXlab platform.
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Influence of Convex and Concave Curvatures in a Coastal Dike Line on Wave Run-up
Water, 2019Co-Authors: Suba Periyal Subramaniam, Corrado Altomare, Babette Scheres, Malte Schilling, Sven Liebisch, Nils B. Kerpen, Torstern Schlurmann, Holger SchüttrumpfAbstract:Due to climatic change and the increased usage of Coastal areas, there is an increasing risk of Dike failures along the coasts worldwide. Wave run-up plays a key role in the planning and design of a Coastal structure. Coastal engineers use empirical equations for the determination of wave run-up. These formulae generally include the influence of various hydraulic, geometrical and structural parameters, but neglect the effect of the curvature of Coastal Dikes on wave run-up and overtopping. The scope of this research is to find the effects of the Dike curvature on wave run-up for regular wave attack by employing numerical model studies for various Dike-opening angles and comparing it with physical model test results. A numerical simulation is carried out using DualSPHysics, a mesh-less model and OpenFOAM, a mesh-based model. A new influence factor is introduced to determine the influence of curvature along a Dike line. For convexly curved Dikes (αd = 210° to 270°) under perpendicular wave attack, a higher wave run-up was observed for larger opening angles at the center of curvature whereas for concavely curved Dikes (αd = 90° to 150°) under perpendicular wave attack, wave run-up increases at the center of curvature as the opening angle decreases. This research aims to contribute a more precise analysis and understanding the influence of the curvature in a Dike line and thus ensuring a higher level of protection in the future development of Coastal structures.
Richard Dawson - One of the best experts on this subject based on the ideXlab platform.
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Costs of sea Dikes
2019Co-Authors: Stephan Lenk, Richard Dawson, Diego Rybski, Oliver Heidrich, Jürgen P. KroppAbstract:Failure to consider the costs of adaptation strategies can be seen by decision makers as a barrier to implementing Coastal protection measures. In order to validate adaptation strategies to sea-level rise in the form of Coastal protection, a consistent and repeatable assessment of the costs is necessary. This paper significantly extends current knowledge on cost estimates by developing - and implementing using real Coastal Dike data - probabilistic functions of Dike costs. Data from Canada and the Netherlands are analysed and related to published studies from the US, UK, and Vietnam in order to provide a reproducible estimate of typical sea Dike costs and their uncertainty. We plot the costs divided by Dike length as a function of height and test four different regression models. Our analysis shows that a linear function without intercept is sufficient to model the costs, i.e. fixed costs and higher-order contributions such as that due to the volume of core fill material are less significant. We also characterise the spread around the regression models which represents an uncertainty stemming from factors beyond Dike length and height. Drawing an analogy with project cost overruns, we employ log-normal distributions and calculate that the range between 3x and x/3 contains 95% of the data, where x represents the corresponding regression value. We compare our estimates with previously published unit costs for other countries. We note that the unit costs depend not only on the country and land use (urban/non-urban) of the sites where the Dikes are being constructed but also on characteristics included in the costs, e.g. property acquisition, utility relocation, and project management. This paper gives decision makers an order of magnitude on the protection costs, which can help to remove potential barriers to develop-ing adaptation strategies. Although the focus of this research is sea Dikes, our approach is applicable and transferable to other adaptation measures.
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Costs of sea Dikes – regressions and uncertainty estimates
Natural Hazards and Earth System Sciences, 2017Co-Authors: Stephan Lenk, Richard Dawson, Diego Rybski, Oliver Heidrich, Jürgen P. KroppAbstract:Abstract. Failure to consider the costs of adaptation strategies can be seen by decision makers as a barrier to implementing Coastal protection measures. In order to validate adaptation strategies to sea-level rise in the form of Coastal protection, a consistent and repeatable assessment of the costs is necessary. This paper significantly extends current knowledge on cost estimates by developing – and implementing using real Coastal Dike data – probabilistic functions of Dike costs. Data from Canada and the Netherlands are analysed and related to published studies from the US, UK, and Vietnam in order to provide a reproducible estimate of typical sea Dike costs and their uncertainty. We plot the costs divided by Dike length as a function of height and test four different regression models. Our analysis shows that a linear function without intercept is sufficient to model the costs, i.e. fixed costs and higher-order contributions such as that due to the volume of core fill material are less significant. We also characterise the spread around the regression models which represents an uncertainty stemming from factors beyond Dike length and height. Drawing an analogy with project cost overruns, we employ log-normal distributions and calculate that the range between 3x and x∕3 contains 95 % of the data, where x represents the corresponding regression value. We compare our estimates with previously published unit costs for other countries. We note that the unit costs depend not only on the country and land use (urban/non-urban) of the sites where the Dikes are being constructed but also on characteristics included in the costs, e.g. property acquisition, utility relocation, and project management. This paper gives decision makers an order of magnitude on the protection costs, which can help to remove potential barriers to developing adaptation strategies. Although the focus of this research is sea Dikes, our approach is applicable and transferable to other adaptation measures.
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Adaptive importance sampling for risk analysis of complex infrastructure systems
Proceedings of the Royal Society A: Mathematical Physical and Engineering Sciences, 2006Co-Authors: Richard Dawson, Jim W. HallAbstract:Complex civil infrastructure systems are typically exposed to random loadings and have a large number of possible failure modes, which often exhibit spatially and temporally variable consequences. Monte Carlo (level III) reliability methods are attractive because of their flexibility and robustness, yet computational expense may be prohibitive, in which case variance reduction methods are required. In the importance sampling methodology presented here, the joint probability distribution of the loading variables is sampled according to the contribution that a given region in the joint space makes to risk, rather than according to probability of failure, which is the conventional importance sampling criterion in structural reliability analysis. Results from simulations are used to intermittently update the importance sampling density function based on the evaluations of the (initially unknown) risk function. The methodology is demonstrated on a propped cantilever beam system and then on a real Coastal Dike infrastructure system in the UK. The case study demonstrates that risk can be a complex function of loadings, the resistance and interactions of system components and the spatially variable damage associated with different modes of system failure. The methodology is applicable in general to Monte Carlo risk analysis of systems, but it is likely to be most beneficial where consequences of failure are a nonlinear function of load and where system simulation requires significant computational resources.
Xuexue Chen - One of the best experts on this subject based on the ideXlab platform.
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Vulnerability of Buildings on Coastal Dikes due to Wave Overtopping
Water, 2017Co-Authors: Xuexue Chen, Sebastiaan N. Jonkman, Sander Pasterkamp, Tomohiro Suzuki, Corrado AltomareAbstract:The vulnerability of buildings on Coastal Dikes due to overtopping wave impacts is difficult to assess. A method is developed in this paper to quantify the vulnerability of masonry buildings on a Coastal Dike exposed to wave overtopping. Using previous studies, the accidental loads due to the extreme wave impacts are characterized. Using the approach from Eurocode 6, the strength of masonry buildings under these loads is assessed. Results from a case study in Belgium show that masonry buildings located 10–15 m away from the seafront would suffer from localized damage, such as windows being broken under a 1000 year storm. The building would collapse under a 10,000-year storm. The method can be used to assess the safety of existing buildings on Coastal Dikes and to design new buildings.
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Case Study: Wenduine, Belgium : Vulnerability of buildings on a Coastal Dike
2017Co-Authors: Xuexue ChenAbstract:On Coastal Dikes in Belgium, many residential buildings are found. Most of the old buildings are masonry structures with two to three floors (Figure 1). The ground floors are always elevated (Figure 2), and the entrances of the basements are closed by shutters (Figure 3). The most modern buildings are concrete reinforcement structures with concrete piles/columns as foundations. The walls are consisting of masonry or concrete. These buildings are 5 to 9 floors high. Some of the ground floors are elevated, and some are used as cafe, restaurant or store. The ground floors are equipped with large glass windows and doors.
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Predicting wave impact on structures on top of a levee
2017Co-Authors: Xuexue ChenAbstract:In low-lying countries like the Netherlands and Belgium, Coastal areas are often highly urbanized, and buildings are often built on or close to the flood defenses (Figure 2 shows a typical Belgian seaside town). This is an example of multifunctional flood defense, where urban functions are integrated with flood defense structures. In this example, the wide crest of the Coastal Dike is used as a promenade with building frontage. However, policy makers as well as the users and owners of the properties may be unaware of possible overtopping effects, and they may lack records of wave overtopping and the potential direct damage it can cause. The goal of this research project was to develop a tool that can measure the risks and potential cost of wave overtopping events on buildings.
Suba Periyal Subramaniam - One of the best experts on this subject based on the ideXlab platform.
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Influence of Convex and Concave Curvatures in a Coastal Dike Line on Wave Run-up
Water, 2019Co-Authors: Suba Periyal Subramaniam, Corrado Altomare, Babette Scheres, Malte Schilling, Sven Liebisch, Nils B. Kerpen, Torstern Schlurmann, Holger SchüttrumpfAbstract:Due to climatic change and the increased usage of Coastal areas, there is an increasing risk of Dike failures along the coasts worldwide. Wave run-up plays a key role in the planning and design of a Coastal structure. Coastal engineers use empirical equations for the determination of wave run-up. These formulae generally include the influence of various hydraulic, geometrical and structural parameters, but neglect the effect of the curvature of Coastal Dikes on wave run-up and overtopping. The scope of this research is to find the effects of the Dike curvature on wave run-up for regular wave attack by employing numerical model studies for various Dike-opening angles and comparing it with physical model test results. A numerical simulation is carried out using DualSPHysics, a mesh-less model and OpenFOAM, a mesh-based model. A new influence factor is introduced to determine the influence of curvature along a Dike line. For convexly curved Dikes (αd = 210° to 270°) under perpendicular wave attack, a higher wave run-up was observed for larger opening angles at the center of curvature whereas for concavely curved Dikes (αd = 90° to 150°) under perpendicular wave attack, wave run-up increases at the center of curvature as the opening angle decreases. This research aims to contribute a more precise analysis and understanding the influence of the curvature in a Dike line and thus ensuring a higher level of protection in the future development of Coastal structures.