波致海底缓倾角无限坡滑动稳定性计算分析探讨

波浪作用下海底无限坡滑动稳定性计算的极限平衡法中,忽略了坡体水平向应力状态的影响,为此,针对波浪作用下海底缓倾角无限边坡的特点,提出直接基于滑动面处土体应力状态的滑动稳定性计算方法(简称应力状态法),并分析了其适用范围。对具体算例的分析表明,应力状态法计算得出的安全系数大于极限平衡法的安全系数,且随着滑动面深度的增加、土体泊松比以及边坡坡角的增大,两种计算方法得出的安全系数的差异会逐渐增大;对于波浪作用下的海底缓倾角无限边坡,在失稳时极可能沿具有一定厚度的滑动带而不是单一的滑动面而滑动,且波致最大剪应力所在的深度,常常不是斜坡体最易失稳滑移的深度。

Wave-induced stability analysis on submarine infinite slope with gentle dip angle

For wave-induced stability analysis on submarine infinite slopes,the limit equilibrium method generally ignores horizontal stresses acting in the soil deposit. On basis of describing the characteristics of the submarine infinite slope under wave action and considering the soil stress state at the slip surface,this study proposed a stress analysis method to analyze sliding stability of the submarine infinite slope,and discussed the applicable prospect of the method. A case study of a submarine infinite slope has been conducted by both of the limit equilibrium method and the proposed stress analysis method. The results have shown that the factor of safety by the stress analysis method is greater than that of the limit equilibrium method,and the differences of factors obtained by the two methods become larger with increasing depth of the slip surface,Poisson ratio of the soil deposit and dip angle of the infinite slope. For a submarine infinite slope with gentle dip angle under wave action,it may slide along a slip zone rather than a single slip surface under unstable state,and the depth for the maximum shear stress does not generally indicate the most instability location of the infinite slope.