MPM study of water wave interaction with porous seawalls
type: CreativeWork
description: Flood defences are becoming increasingly vital for protecting key coastal infrastructure from rising sea levels and storm surge waves. Waves attenuate rapidly as they propagate through porous media, corresponding to significant energy dissipation. The ability of porous armour layers to absorb wave energy is therefore of great interest to hydraulic engineers, as more and more natural and artificial porous structures are constructed to defend vulnerable coastlines or existing flood defences from wave attack. Design parameters for permeable flood defences include the grain size of the sediment particles that form the barrier and the width of the barrier. Previous studies have demonstrated that the runup height, which determines the risk of overtopping, is primarily dependent on the still water depth, wave amplitude and ground slope. This thesis investigates the effect of manipulating the mean grain size of a permeable barrier on the runup response to a dam-break flood wave and a solitary wave using the Material Point Method (MPM). Traditional methods for ascertaining the stability of protective barriers have used small-scale physical models, however, these are expensive and have been shown to suffer from scaling problems. Numerical methods are therefore gaining popularity in flood risk management applications. MPM is capable of handling large deformation problems within a Lagrangian framework, allowing for simple application of boundary conditions. MPM has been widely used to solve solid mechanics problems with history-dependent variables, but the application of this method to fluid mechanics has been rare. In MPM, the background mesh is only used to solve the governing equations. The material properties are stored at the material points so that issues arising from mesh distortions such as those exhibited in the classical finite element method (FEM) are easily avoided when coping with large deformations. Although it stores no permanent information, the background mesh …
abstract: Flood defences are becoming increasingly vital for protecting key coastal infrastructure from rising sea levels and storm surge waves. Waves attenuate rapidly as they propagate through porous media, corresponding to significant energy dissipation. The ability of porous armour layers to absorb wave energy is therefore of great interest to hydraulic engineers, as more and more natural and artificial porous structures are constructed to defend vulnerable coastlines or existing flood defences from wave attack. Design parameters for permeable flood defences include the grain size of the sediment particles that form the barrier and the width of the barrier. Previous studies have demonstrated that the runup height, which determines the risk of overtopping, is primarily dependent on the still water depth, wave amplitude and ground slope. This thesis investigates the effect of manipulating the mean grain size of a permeable barrier on the runup response to a dam-break flood wave and a solitary wave using the Material Point Method (MPM). Traditional methods for ascertaining the stability of protective barriers have used small-scale physical models, however, these are expensive and have been shown to suffer from scaling problems. Numerical methods are therefore gaining popularity in flood risk management applications. MPM is capable of handling large deformation problems within a Lagrangian framework, allowing for simple application of boundary conditions. MPM has been widely used to solve solid mechanics problems with history-dependent variables, but the application of this method to fluid mechanics has been rare. In MPM, the background mesh is only used to solve the governing equations. The material properties are stored at the material points so that issues arising from mesh distortions such as those exhibited in the classical finite element method (FEM) are easily avoided when coping with large deformations. Although it stores no permanent information, the background mesh …
author: Harris, Lucy
language: eng
keywords: MPM, porous media, flooding, flood defences
license: https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/9e1626f8-b39d-4211-bea9-721a491d3569/download
license: https://www.rioxx.net/licenses/all-rights-reserved/
date published: 2020-06-01
date modified: 2026-07-22T22:24:14Z
provider: Cambridge University
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Cambridge

PropertyValue
property ID: DOI
value: 10.17863/CAM.59054