某水利枢纽工程左岸坝前堆积体经历了5·12汶川大地震及4·20雅安地震，其内部的物理力学参数发生了恶化，稳定性有所降低。尽管现在该堆积体整体是稳定的，一旦再次经历类似的地震，其整体稳定状况会更加恶化，将对下游水利枢纽工程的安全稳定运行产生重大影响。运用FLAC^3D数值模拟方法和Newmark法计算堆积体边坡在地震作用下的永久位移是很有必要的。计算结果表明地震作用下堆积体发生位移部位主要位于压重体上方的小部分范围，产生的最大位移为0.56 m，同时根据位移和塑性区情况判断了堆积体的稳定性。最终预测出在类似的地震作用下，堆积体只会发生局部的浅表层蠕滑，整体仍是稳定的，研究成果为保证下游水利枢纽的安全稳定运行提供依据。

Having experienced 5·12 Wenchuan earthquake and 4·20 Ya’an earthquake, the left bank accumulation body in front of a hydro-junction has degraded in its stability and physico-mechanical parameters. Although the accumulation body is stable in general at present, its overall stability will have a significant impact on the safe and stable operation of downstream hydro-junction when similar earthquake occurs again. In view of this, we calculated the permanent displacement of the accumulation body under earthquake action by using FLAC^3D and Newmark Method. We conclude that the displacement of the accumulation body is mainly located in the small part above the pressure body, and the maximum displacement is 0.56m. Furthermore, we estimated the stability of the accumulation body according to the displacement and plastic zone. The accumulation body will still be stable as a whole under similar earthquakes, with only local shallow surface creep. The result offers a basis for ensuring the safe and stable operation of the downstream hydro-junction.