运用有限差分软件FLAC3D，建立了呷爬滑坡体三维模型，分别施加1倍和3倍El-Centro地震波。计算结果表明，1倍地震波作用下会发生一定的永久位移，但不会滑动失稳；3倍地震波作用下将发生滑动失稳。进一步发现边坡在1倍和3倍地震波激励下的变形滑移特征不同，第一种情况属于累积效应阶段，变形主要集中于滑体Ⅲ，第二种情况属于触发效应阶段，滑体Ⅰ的滑动变形同样剧烈。文中从滑坡体的组成物质和材料参数、滑动区域的地形因素和滑动区域的动力响应三方面进行了分析。运用Newmark有限滑动位移法，基于滑体Ⅰ和滑体Ⅲ的加速度响应时程，计算了两者的永久位移，结果与数值计算吻合良好。表明滑体Ⅲ处的动力响应会产生更大的永久位移，从而验证了数值计算的结果。同时，基于结构动力响应而计算得到的永久位移也可以作为衡量地震作用对该处结构变形影响的指标，从而估计地震对局部结构的破坏作用。

The three-dimensional Gapa landslide model is established by using the finite difference software FLAC3D. The El-Centro seismic acceleration history is selected as the dynamic excitation, and it is multiplied by the magnification factors 1 and 3, respectively. The calculation results show that the permanent displacement of slope will occur when the magnification factor equals to 1, but it will not slide; when seismic history is multiplied by 3, the slope will slide. Moreover, the deformation characteristics are different under the seismic excitation with different magnification factor. In the first case deformation mainly concentrated on the sliding body Ⅲ, but in the second case the deformation of sliding body Ⅰ is much more intense. This paper analyzed this phenomenon in three aspects of the parameters of composition material, the topographic factor and the dynamic characteristics of slope. The permanent displacement is calculated by Newmark finite sliding displacement method and the results meet the numerical calculation well. It shows that the sliding body Ⅲ has the greater permanent displacement due to the dynamic characteristics of slope. Also, the permanent displacement can also be used as the index for the effect of earthquake on local deformation to estimate the damage of earthquake.

国家科技支撑计划（2013BAB05B05）