波浪作用下黏性土海床动力响应数值分析

波浪作用下黏性土海床的动力响应对于海洋建筑物的稳定性具有重要的影响。在大型有限元软件ABAQUS平台上进行二次开发,根据重复性原理(repeatability principle)在有限元模型中设置侧向边界条件,采用Carter等(1982)提出的改进剑桥动力本构模型模拟海床土体。首先通过与有关弹性海床在波浪荷载作用下力学响应的解析解的对比,在一定程度上验证了有限元模型的合理性。进而通过参数对比研究,探讨了波高、波浪周期、海床土体的渗透系数等因素对于弹塑性黏性土海床力学响应的影响。计算结果表明,在波高较大、周期较短、土的渗透系数较低情况下,容易导致黏性土海床丧失稳定性。

Numerical Analyses for Dynamic Response of Clayey Seabed under Wave Loading

The effect of dynamic response of clayey seabed on the stability of marine structures under wave loading is appreciably large.Based on the FEM software ABAQUS,the lateral boundary in the FE model is set up according to repeatability principle,and the clayey soil is simulated by utilizing the improved Cam-clay dynamic constitutive model proposed by Carter et al (1982).Compared with the relevant analytical solutions for behavior of elastic seabed under wave loading,the present FE model was validated firstly.Then,the parametric studies are conducted to explore the effect of some factors,such as wave height,wave period and permeability coefficient etc.on the dynamic response of elasto-plastic clayey seabed.The computational results indicate that the clayey seabed tends to instability more likely under the conditions of larger height wave,shorter wave period and lower permeability coefficient.