Waves attenuate rapidly as they propagate through porous media due to significant energy dissipation. The ability of permeable armour layers to absorb wave energy is therefore of great interest to the researchers and engineers tasked with the construction of structures that defend vulnerable coastlines from the wave attack. The goal of this research is to determine the effectiveness of vertical and sloped permeable barriers in minimising the wave run-up. Traditional methods for ascertaining the efficacy of protective barriers have used small-scale physical models. However, these are expensive and have been shown to suffer from the scaling problems, therefore numerical methods are gaining popularity. This paper investigates the effect of modifying the mean grain size of a permeable barrier on the run-up response to a solitary wave, using the Material Point Method (MPM), which is capable of handling large deformation problems within a Lagrangian framework, with a background mesh facilitating the solution of the governing equations and allowing for simple imposition of the boundary conditions. A double-point MPM is adopted, with two sets of material points representing the solid and liquid phases respectively, to accurately model situations where the fluid moves through the solid skeleton, such as in the case of wave run-up on porous structures. The multi-phase version of the MPM package Anura3D (www.anura3d.com) is used in the study, with a focus on the influence of changing the mean grain size of composition particles of a porous structure on solitary wave run-ups, on both vertical and sloped permeable boundaries. It has been shown that with an increase in the mean grain size, and therefore the permeability, the overall wave run-up height can be significantly reduced. The proposed study could contribute to a better understanding on the wave run-up reduction on porous structures, and provide useful design guidelines to the coastal defences.

由于大量的能量消散，波在通过多孔介质传播时会迅速衰减。因此，研究人员和工程师对可渗透的防护层吸收波浪能量的能力非常感兴趣，他们需要负责建造能够保护脆弱海岸线免受波浪袭击的结构。这项研究的目的是确定垂直和倾斜的渗透屏障在最小化波浪传播方面的有效性。确定保护性屏障功效的传统方法已使用小型物理模型。但是，这些方法很昂贵，并且已经显示出存在缩放问题，因此数值方法越来越受欢迎。本文研究了修改可渗透势垒的平均晶粒尺寸对孤波上升响应的影响，使用“材料点方法”（MPM），该方法能够处理拉格朗日框架内的较大变形问题，并且背景网格有助于控制方程式的求解，并允许简单施加边界条件。采用双点MPM，两组物质点分别代表固相和液相，以精确地模拟流体在固体骨架中移动的情况，例如在多孔结构上的波前情况。在研究中使用了MPM软件包Anura3D（www.anura3d.com）的多阶段版本，重点是改变多孔结构的组成粒子的平均粒径对孤立波上升的影响。垂直和倾斜的渗透边界。已经表明，随着平均晶粒尺寸的增加以及因此磁导率的增加，总波上升高度可以显着减小。拟议的研究可以有助于更好地了解多孔结构的波径减少，并为沿海防御提供有用的设计指南。