城区复杂环境岩溶地面塌陷灾害成因与致灾规律研究——以贵港市北环新村岩溶地面塌陷灾害为例

岩溶地面塌陷是岩溶发育地区常见的地质灾害类型。岩溶塌陷对基础设施和人民生命财产安全构成极大威胁。文章以贵港市北环新村岩溶地面塌陷灾害为例，采用地质分析与颗粒流离散元数值模拟相结合的方法，研究岩溶塌陷成因与致灾规律。结果表明:本次塌陷是由多类因素共同导致，主要包括地质环境、地下水位波动与管道渗漏及工程建设活动等；白云岩、灰岩差异性风化所形成的粉砂质土极易诱发土洞与岩溶塌陷灾害；塌陷灾害可分为土洞形成阶段、土洞发展阶段和土洞塌陷阶段，其土洞规模、形状及影响存在显著差别；土洞形成发展过程中，地表沉降量从塌陷中心向四周逐渐减小，存在明显的沉降敏感区，塌坑边缘的竖向临空面存在拉应力作用，极易再次诱发塌陷。研究成果可为岩溶地面塌陷灾害防控与预警提供一定的理论参考。 

Cause and law of karst collapse in the urban complex environment:An example of Beihuanxincun, Guigang City

In karst areas， ground collapse is a common geological hazard， which poses a great threat to the safety of infrastructure and people's lives and properties. Taking Beihuanxincun， Guigang city as an example， this paper studies the cause of the karst collapse and the law of its hazard by using the methods of geological analysis and particle flow discrete element numerical simulation. The results show that this collapse is caused by many factors， including the geological environment， groundwater level fluctuation， pipeline leakage and engineering construction activities. The silty soil formed by differential weathering of dolomite and limestone is easy to induce collapse of soil caves and karst. The collapse hazard can be divided into three stages: formation， development and the collapse. There are significant differences in the size， shape and influence of soil caves in different stages. During the formation and development of the soil cave， the surface settlement gradually decreases from the collapse center to the surrounding area， with existence of obvious settlement sensitive areas. The vertical free face at the edge of the collapse pit has tensile stress， which is easy to induce collapse again. The research results can provide a theoretical reference for prevention and early warning of karst ground collapse.