波浪荷载作用下各向异性海床瞬态液化研究  

Numerical Study on Wave-Induced Oscillatory Liquefaction in Anisotropic Seabed

作　　者：段伦良 郑东生[1] 王少华 张启博 DUAN Lunliang;ZHENG Dongsheng;WANG Shaohua;ZHANG Qibo(School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China)

机构地区：[1]西南交通大学土木工程学院

出　　处：《西南交通大学学报》2019年第4期741-747,共7页Journal of Southwest Jiaotong University

基　　金：国家自然科学基金资助项目(41176073)

摘　　要：为探究各向异性海床在波浪作用下的瞬态液化问题,采用有限元法求解RANS(reynolds averaged navier-stokes)方程及k-ε湍流模型进行数值造波,通过求解Biot多孔弹性方程获得海床瞬态响应,进而建立了波浪-各向异性海床耦合作用的二维数值仿真模型.在完成对新建模型的验证后,基于此模型系统地研究了波浪及海床特性对各向异性海床瞬态液化的影响.研究结果表明:海床瞬态液化深度随波高、周期增大而增大,随海床饱和度增大而减小;当海床垂向渗透系数在一定范围内时,海床最大液化深度随垂向渗透系数增大而减小,超出该范围时,海床垂向渗透系数对海床最大液化深度的影响不明显;海床瞬态液化深度对水平方向渗透系数的改变不敏感.In order to investigate the wave-induced oscillatory liquefaction in an anisotropic seabed,a two-dimensional numerical model for wave-seabed interactions is proposed.The reynolds-averaged navier-stokes(RANS)equation with the standard k-εturbulence model was used to describe wave motions,and Biot’s poro-elastic equation was taken as the governing equation for the seabed model.After validation with previous experimental data and analytical solution,the proposed model was further applied to investigate the effects of wave and soil characteristics on anisotropic soil liquefaction.Numerical results show that the maximum liquefaction depth increased with an increase in wave height and wave period,and decreased with the degree of soil saturation.When the value of the soil permeability coefficient along the vertical direction is within a certain range,the effects of soil permeability along the vertical direction on the wave-induced soil response are obvious.Beyond the range,however,the effects of soil permeability along the vertical direction are almost negligible.Besides,the wave-induced oscillatory liquefaction depth in an anisotropic seabed is not sensitive to the variations in soil permeability along the horizontal direction.

关 键 词：液化 RANS方程 BIOT方程 海床 各向异性 

分 类 号：V355[航空宇航科学与技术—人机与环境工程]