Porous Models for Wave-induced Seabed Liquefaction

Abstract

Marine geotechnics is a multidiscipline research topic covering conventional civil engineering disciplines such as fluid mechanic, coastal engineering, geotechnical engineering, and structures engineering. This research field has attracted great attention among coastal and geotechnical engineers since the 1980s due to the growing activities in offshore environments. An appropriate design of foundations of marine infrastructures, such as breakwaters, offshore pipelines, platforms, and offshore wind turbine foundations, plays an important role in the success of offshore engineering projects. Therefore, the evaluation of the wave-induced soil response and its resultant seabed instability is particularly important for coastal engineers involved in the design of marine infrastructures. When water waves propagate in the ocean, they generate significant dynamic pressures on the sea floor. These dynamic pressure variations further induce pore water pressure and effective stresses within the seabed. With excess pore water pressure and diminishing vertical effective stress, part of the seabed may become unstable or even liquefied. Once liquefaction occurs, the soil particles are likely to be carried away as a heavy fluid by any prevailing bottom current or mass transport owing to the action of ocean waves.