Integrated prediction of 3D wave-induced liquefaction around breakwater heads

沿海区是一个独特的地质、自然和生物区域，具有重要的经济、文化和环境价值。世界三分之二以上的人口集中在沿海地区，那里的海岸线对贸易、运输、旅游、休闲和海洋食物的收获要么是中心地带，要么是非常重要的地带。防波堤通常用于保护和提高海岸线的效用。在世界范围内，每年建造新防波堤和维护现有防波堤的总成本约为数百亿英镑，防波堤容易受到海床地基液化的影响，这一过程往往会导致地基在建造后短短几年内严重退化，有时甚至导致完全坍塌。防波堤的设计或维护不当会导致灾难性的海岸灾害。例如，葡萄牙西内斯防波堤的倒塌造成的损失仅重建就相当于近10亿美元，这还不包括对该地区的巨大经济和社会影响。最近的一个例子是新奥尔良在卡特里娜飓风期间，由于防波堤失效而造成的沿海悲剧，使该市80%的地区淹没在6米深的水下，造成人员死亡和个人和经济混乱。在本研究中，我们首先将现有的二维波浪和土壤模型扩展到三维，然后将它们整合到一个单一的模型中，以提供更好的预测防波堤头周围的波浪诱导液化。为了验证所提出的理论模型，将进行一系列的物理模型实验。拟议的研究是朝着显著改进工程设计和补救行动以解决与地基有关的沿海结构损坏问题迈出的重要一步。该项目的基本概念创新来自三个因素，这些因素结合联合收割机，使人们能够正确理解WSSI现象：1）防波堤头周围波浪/海床相互作用的所有三个组成部分的整合; 2）将海床作为具有大变形的一般多孔介质处理; 3）使用3D而不是2D建模。这种方法是必不可少的，因为它是唯一的方法来模拟防波堤头周围的波浪模式，海洋沉积物中的波浪能量耗散模型（包括通过多孔介质的流动的临界现象），并充分考虑波浪，海床和结构之间的相互作用。.

The coastal zone is a unique geological, physical and biological area of vital economic, cultural and environmental value. More than two-thirds of the world's population is concentrated in coastal zones, where the coastline is either central or of great importance to trade, transport, tourism, leisure and the harvesting of marine food. Breakwaters are commonly adopted to protect and enhance the utility of coastlines. Worldwide, the combined costs for building new breakwaters and maintaining the existing ones are in the order of tens of billions of pounds a year.Breakwaters are vulnerable to the liquefaction of the seabed foundation, a process that can often lead to significant degradation of the foundation in as little as a few years after construction and sometimes even result in total collapse. The inappropriate design or maintenance of breakwaters can lead to catastrophic coastal disaster. For example, the failure of Sines Breakwater in Portugal caused damage equivalent to almost US$1 billion in reconstruction alone, excluding the huge economic and social impacts on the region. A recent example of coastal tragedy due to failure of breakwaters is that of New Orleans during Hurricane Katrina, putting 80% of the city under as much as 6 m of water and causing deaths and personal and economic chaos. The economic loss from the disaster was more than US$15 billion.In this study, we will firstly extend the existing 2D wave and soil models to 3D, and then integrate them into a single model to provide a better prediction of the wave-induced liquefaction around breakwater heads. A series of physical model experiments will be conducted for the verification of the proposed theoretical models. The proposed research is an essential step towards significantly improved engineering design and remedial action to address foundation-related damage to coastal structures. The underlying conceptual innovation of the project comes from three factors that combine to enable the proper understanding of the WSSI phenomenon: 1) the integration of all three components of wave/seabed interactions around breakwater heads; 2) the treatment of the seabed as a general porous media with large deformation; and 3) the use of 3D rather than 2D modelling. This approach is essential as it is the only way to simulate wave patterns around breakwater heads, model wave energy dissipation in marine sediments (including the critical phenomenon of flow through porous media) and account fully the interactions between waves, seabed and structures. .