波浪作用下的海床响应及其对建筑物稳定性的影响

Seabed response to waves and influence on stability of structures

应用动弹性固结有限元法，求解了随机波浪作用下饱和海床土体中的孔隙水压力、有效应力和位移的瞬态响应，并对海洋建筑物的稳定性进行分析。建立的有限元计算模型中采用了动弹性固结理论和线性渗流理论，海床可为具有任意边界条件的分层分块弹性多孔介质；利用简单条分法对海床和建筑物进行稳定性分析，在滑动面上考虑波浪附加应力的影响。孔隙水压力响应的理论计算结果与模型实验的量测值吻合的较好。计算表明，近海工程中考虑海床土体受到的波浪附加应力时，海床和建筑物的整体稳定安全系数将降低，降低幅度主要与海床面上的波浪压力、海床的渗透性有关。

A consolidation finite element method is presented to solve the transient response of seabed, and an improved circular slip method is developed to analyze the stability of coastal structures. Dynamic elastic consolidation theory and linear permeability theory are employed to get a solution for the responses of pore pressure, displacements and effective stresses in a saturated seabed with arbitrary boundary conditions under the action of regular and irregular waves. The influence of wave induced excess stresses on the slip surface is considered in the stability analysis. The spatial and temporal variations of pore pressure compare well with experiments. Calculations show that if the influence of wave induced seabed response is considered, the stability coefficient of coastal structures will decrease, and it is related to wave amplitude and the permeability of seabed soil.