中文摘要：

虽然充填采矿法适应性强,充填体对覆岩移动有较好的控制作用,但其上覆岩层的突变失稳仍然会发生。基于金川龙首矿西二采区覆岩失稳导致地表突然塌陷的实例,对此次事件的发生机理进行了初步分析。在对塌陷区进行调查及地表变形监测的基础上,得出导致覆岩失稳的四大因素：F8断层、采动附加应力、采区特殊地质条件以及充填开采方式;对矿山上覆岩层的失稳过程进行了概化模型分析,事件发生的过程可分为3个阶段：压力拱模型阶段、断层滑移阶段、悬臂梁模型阶段。

英文摘要：

The backfilling mining,widely used,has good effect on controlling overlying rock movement.But sudden collapse also occurred in No.2 west mining area of Longshou Mine in Jinchang Nickel Mine.For this emergency,mechanism of preliminary analysis has been done.There are four factors by investigation and monitoring in collapse area：F8 fault,subsidiary stress of mining,special geological conditions of mining area,and backfilling method.We also built a sketch model for analyzing failure process and divided it into three stages：pressure balance arch stage,fault slipping stage,and cantilever beam stage.