波浪荷载引起不同埋深管线周围海床响应和液化分析

Wave-Induced Seabed Response and Liquefaction Around Pipeline at Different Buried Depths

为了研究波浪荷载引起海底管线周围海床的液化问题,以Biot方程的部分动力响应模型,即u-p模型为基础建立二维埋管海床数值模型,研究海底管线及其周围海床在波浪荷载作用下的动态响应问题,波浪荷载通过孔压边界施加到海床表面.在验证模型的基础上,研究埋管海床在波浪荷载作用下的响应与液化,分析不同管线埋深下海床土的孔压、竖向有效应力和液化范围的区别,并探讨波高、海床土渗透系数和饱和度等参数的影响.结果表明:管线埋深对周围海床土在波浪荷载作用下的响应和液化影响明显;管线的存在使得管线周围海床土的竖向有效应力出现应力集中现象;波高、海床土的渗透系数和饱和度对波浪引起管线周围海床土的响应影响明显.研究结果对海底管线在海洋环境中的安全稳定提供理论依据.

In order to study the liquefaction of the seabed around the pipeline under wave loading,a two-dimensional numerical model was established based on Biot’s partly dynamic equation(u-p model).The dynamic response of the seabed around the pipeline under wave loading was investigated in detail,and the wave loading was applied on the seabed surface through pore pressure boundary.Based on the validation of the numerical model,the response and liquefaction of the seabed around the pipeline under wave loading were studied.The pore pressure,vertical effect stress,and liquefaction range of the seabed at different pipeline buried depths were investigated and the effects of wave height,soil permeability,and saturation were discussed.The results show that the pipeline buried depth has significant effects on the response and liquefaction of seabed under wave loading.The pipeline induces the vertical effective stress concentration of seabed around the pipeline.The effects of wave height,soil permeability,and saturation on the seabed response under wave loading are significant.The results provide a theoretical basis for the safety and stability of submarine pipeline in marine environment.