According to the analysis of a variety of reconnaissance method to access data,the subsidence of the study belongs to karst area,covering soil in karst strata above the gradation of poor soil. With the creep in the long⁃term groundwater evolution process,the fine grained soil by continual seepage was carried away,making the soil formation of concealed“hole”formation. Accordingly,the soil shear strength gradually reduced,in a huge storm floods under the hydrodynamic action,the concealed“hole”formation collapse suddenly. And the loose soil was carried by the flood into the underlying limestone karst formation,resulting in the river surface collapse. Engineering measures such as horizontal impervious blanket,vertical grounting,dynamic compaction,were suggusted for the ground subsidence governance.%根据多种勘察方法取得资料分析，本研究的塌陷区属于覆盖型岩溶区，覆盖在岩溶地层之上的土体属级配不良的土体，在长期的地下水潜蚀演化过程中，土体中的细粒不断被渗流携走，使土体形成隐伏“土洞”地层，土体抗剪强度逐渐降低，在巨大的暴雨洪水水动力作用下隐伏的“土洞”地层突然坍塌，松散的土体被洪水携带流入下伏灰岩岩溶地层，最终造成河道地面塌陷。对地面塌陷区应采取水平防渗铺盖、垂直灌浆、强夯密实等工程措施进行治理。
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