浅水区波浪非线性效应对砂质海床动力响应的影响

以广义Biot动力固结理论为基础，运用一阶椭圆余弦波和二阶Stokes波等非线性波浪理论考虑浅水区波浪荷载的非线性效应，在时域上采用有限元方法对非线性波浪力作用下饱和砂质海床的动力响应进行了数值求解，并与线性波浪作用下海床动力响应特性进行了对比分析。结果表明，随着波长与水深之比L／d及无量纲参数T(g/d)^1/2的增大，非线性波浪对海床动力响应的影响增大。与线性波浪理论相比，孔隙水压力与有效应力幅值的增大效应非常显著。因此在近海海洋建筑物设计与工程场地评价中，波浪力的非线性特性必须引起注意。

Studies on the effect of non-linear wave loading in shallow water region on dynamic response of sandy seabed

In this study, numerical analyses for solving the generalized Biot's dynamic consolidation equations by virtue of finite element method are performed on dynamic response of sandy seabed subjected to non-linear wave loading in the shallow water region. The seabed is modeled as poro-elastic media and the non-linear wave loading is represented by second-order Stokes'wave theory and first-order cnoidal-wave theory. Numerical results are given for comparative studies. Compared with the numerical results from the linear wave theory, the amplitudes of both pore water pressure and effective pressure computed from the non-linear wave theories increase. It is shown that the linear theory of wave usually under-evaluates the dynamic response of seabed in the shallow water region. Therefore, the effect of non-linear characteristics of wave loading should be taken into consideration in planning and design of various near-shore or offshore constructions and facilities and in evaluation of engineering sites.