A large landslide occurred on May 2, 2014, on the south bank of the Yellow River in Huaipa village, Mianchi County, Henan Province, China. The total volume of the slide was about 4 million m³. The landslide caused serious damage to the water-conveying pipeline at the foot of the slope, which was for water supply from the Yellow River to Manchi County and Yima City. After the event, the engineering geological characteristics, influencing factors and failure mechanism were investigated by field investigation and geological mapping. Then, the failure process and the effect of anti-tipping locked segment were presented by three-dimensional (3D) numerical simulation. The results showed that the destruction of the anti-tipping locked segment in the front edge due to open-pit mining was the main factor of slope failure. The sliding mass, composed of loose silty clay and heavily weathered sandstone and mudstone, and rainfall infiltration were other factors triggering the slide. According to 3D numerical simulation, the stability coefficient of the landslide was 1.35 in natural condition and 1.26 when the sliding body was saturated by continuous rainfall, before the anti-tipping locked segment was destroyed, while the stability coefficient decreased significantly to 1.04 after the anti-tipping strata were destroyed. The whole failure occurred when the sliding mass was saturated by continuous rainfall (the stability coefficient is 0.88). This paper can provide an insight into the effect of anti-tipping locked segment on the failure mechanism of landslide associated with open-pit mining and rainfall.

2014年5月2日，河南省渑池县怀坝村黄河南岸发生大型滑坡。滑动件的总体积约为400万米³. 滑坡对坡脚下供黄河向满池县和义马市供水的输水管道造成严重破坏。事后，通过现场勘察和地质填图，对工程地质特征、影响因素及破坏机理进行了调查。然后，通过三维（3D）数值模拟展示了失效过程和防倾翻锁定段的效果。结果表明，露天开采前缘防倾锁段破坏是边坡失稳的主要因素。由松散粉质粘土和严重风化的砂岩和泥岩组成的滑动体以及降雨入渗是引发滑动的其他因素。根据 3D 数值模拟，自然条件下滑坡体的稳定系数为1.35，连续降雨使滑体饱和时为1.26，抗倾覆锁定段破坏前滑坡稳定系数为1.26，抗倾覆地层破坏后稳定系数显着下降至1.04。整个破坏发生在连续降雨使滑动体饱和时（稳定系数为0.88）。本文可以深入了解抗倾翻锁定段对露天开采和降雨相关滑坡破坏机制的影响。04后防倾覆地层被破坏。整个破坏发生在连续降雨使滑动体饱和时（稳定系数为0.88）。本文可以深入了解抗倾翻锁定段对露天开采和降雨相关滑坡破坏机制的影响。04后防倾覆地层被破坏。整个破坏发生在连续降雨使滑动体饱和时（稳定系数为0.88）。本文可以深入了解抗倾翻锁定段对露天开采和降雨相关滑坡破坏机制的影响。