波浪作用下堤前海床动力反应分析

Dynamic response analysis of seabed in front of seawall under wave loading

基于二维广义Biot动力固结理论,建立了在线性波浪作用下饱和弹性多孔介质堤前海床动力反应的u-p形式有限元方程,采用无条件稳定的隐-隐式交叉迭代法在时域内进行求解.研究表明,当海床地基土饱和度不等于1.0时,超静孔压幅值将显著变化,这时按实际饱和度进行动力分析更为合理;地基土的分层差异将使堤前海床承受剪切的能力发生较大变化;随着反射系数的增大,超静孔压幅值和有效应力幅值明显增大,海床液化程度也明显加剧.

Based on the generalized formulation of two-dimensional Biot＇s dynamic consolidation theory, a finite element equation was set up to evaluate the dynamic response of the elastic seabed in front of seawall subjected to the linear wave loading. Unconditionally stable implicit-implicit staggered solution was adopted to solve the equation in time domain. Numerical calculation shows that the amplitude of excess pore pressure changes obviously when the soil saturation degree is not equal to 1.0, and that it is more rational that the dynamic response is calculated according to the actual saturation. The capacity of bearing shear of seabed in front of seawall changes greatly because of stratified diversity of foundation soil. Along with the increasing wave reflection coefficient, the amplitude of excess pore pressure and the effective stresses apparently increase and the liquefaction depth increases also.