处于海洋环境的桩柱在瑞利波作用下的响应

Research on responses of piles in sea environment subjected to Rayleigh waves

本文以一海洋深水环境桩柱为例,考虑到海洋地基为两相饱和土介质,基于Biot两相饱和多孔介质理论,通过数值算例分析了饱和介质中瑞利波加速度、位移分布规律并与单相弹性介质地基条件下进行了对比,结果表明,瑞利波主要作用于地表附近且振动幅度随深度衰减很快,饱和地基下的瑞利波影响深度要大于单相弹性地基,在瑞利波地震作用下,考虑两相饱和介质下的桩柱位移响应大于单相弹性介质地基。并且由于桩柱处海洋深水环境,本文对环境水体对桩柱振动响应的影响进行了研究,结果表明,流固耦合效应可明显降低桩柱运动响应,在海洋深水环境地震响应分析时,有必要考虑饱和地基以及流固耦合效应对桩柱运动响应的影响。

In this article,the dynamic responses of piles under Rayleigh wave action are investigated.Consider that the offshore foundation is two-phase saturated soil medium,based on Biot＇s theory,the effects of the saturation on velocity and displacement of Rayleigh wave are analyzed by numerical methods and compared with that for half-space base.It is shown that the major influence is near the surface and decays rapidly with depth,especialy in elastic half-space.Under the action of Rayleigh wave,the response of pile is bigger in saturated soil medium.Because the pile is in the deep sea invironment,the influence of fluid-structure coupling effects is investigated.The results show that the effects have great impact on the response of pile in the open sea environment.It is necessary to take two-phase saturated base and fluid-structure coupling effects into the calculation of pile responses to the Rayleigh wave action.