饱和黄土边坡的动力稳定性分析

Analysis of dynamic stability of saturated loess slopes

考虑地震荷载作用下饱和黄土的孔压增长模式及液化规律,建立了饱和黄土无限边坡的动力稳定性分析模型,并将此类边坡的破坏分为液化型破坏和滑动型破坏两种基本类型。分析结果表明,由于孔压的累积,屈服地震系数将随时间而减小,并且明显地受到有效粘聚力、初始孔压比等参数的影响。另外还证实,考虑孔压累积时的永久位移计算值要大于常规的Newmark 法分析的结果。

Based on the increasing mode of pore pressure and the liquefaction mechanism of saturated loess, a model to analyze the dynamic stability of infinite slopes of saturated loess is established. By the model, the failures of this kind of slopes are classified into two modes: one due to liquefaction and another due to sliding. The analytical results indicate that the yield seismic coefficient, which decreases with time, is strongly affected by some soil parameters, i.e. the effective cohesion and initial pore pressure ratio. In addition, it is validated that the value of permanent displacement computed by the model, in which the pore pressure build-up is considered, is greater than by the conventional Newmark method.