为了分析黄土地区地震滑坡的失稳破坏特征，以1920年海原8.5级特大地震诱发的新堡村滑坡为例，在卫星遥感解译、滑坡野外现场调查的基础上，基于滑坡体滑动前与滑动后体积相等的原理，采用MATLAB的数值仿真功能复原新堡村滑坡滑动前原始地形。在此基础上，运用数值模拟方法分析了新堡村滑坡在地震作用下失稳变形破坏特征并反演得到斜坡失稳最小水平地震动。滑坡复原结果表明：新堡村滑坡复原后，斜坡坡面形状整体呈内凹形，坡度的分布范围在12°~18°。数值模拟结果表明：复原后的滑坡在自然条件下，斜坡变形量较小，未出现明显塑性变形区，稳定性较好，整体稳定性系数为1.355。在地震作用下，当输入地震动为0.4g时，稳定性系数为0.887，斜坡处于失稳破坏状态，斜坡体出现了大面积变形，最大变形区域位于坡顶附近，从坡顶至坡脚逐渐减少，推测该滑坡为推移式滑坡。反演得到斜坡失稳最小水平地震动为0.36g，本文研究成果可为黄土地区地震灾害的防治提供一定的基础资料和参考依据。

In order to analyze the instability and failure characteristics of earthquake landslides in the Loess Plateau, the Xinbaocun landslide induced by the 8.5-magnitude Haiyuan earthquake in 1920 was taken as an example. Based on satellite remote sensing interpretation and field investigation of landslides, the original terrain of the Xinbaocun landslide before sliding was restored using the numerical simulation function of MATLAB based on the principle that the volume of the landslide body before and after sliding is equal. On this basis, the numerical simulation method was used to analyze the instability, deformation and failure characteristics of the Xinbaocun landslide under the action of earthquakes and invert the minimum horizontal ground motion of the slope instability. The landslide restoration results show that after the restoration of the Xinbaocun landslide, the slope surface shape is generally concave, and the slope distribution range is 12° ~ 18°. The numerical simulation results show that under natural conditions, the slope deformation of the restored landslide is small, there is no obvious plastic deformation zone, the stability is good, and the overall stability coefficient is 1.355. Under the action of earthquake, when the input earthquake motion is 0.4g, the stability coefficient is 0.887, the slope is in an unstable and damaged state, and the slope body has a large area of deformation. The maximum deformation area is located near the top of the slope, and gradually decreases from the top to the foot of the slope. It is speculated that the landslide is a push-type landslide. The inversion results show that the minimum horizontal earthquake motion for slope instability is 0.36g. The research results of this paper can provide certain basic data and reference for the prevention and control of earthquake disasters in the Loess Plateau.