综合物探在北京地区岩溶塌陷勘查中的应用

北京市海淀区四季青镇香山村普安店在近几年中发生了多起地面塌陷灾害,给当地村民的生命和财产安全造成严重威胁。要查明地面塌陷灾害的成因,必须先要寻找地下隐伏的空洞。在勘查工作区内,采用高密度电阻率法、孔间电磁波CT法相结合的综合物探手段,成功探测出两处地下空洞,经钻探验证为岩溶发育所致。综合研究分析认为:工作区内下伏基岩为灰岩,属于可溶性碳酸盐类岩石;地下水在基岩面附近,且基岩面的高低变化大,在漫长的潜蚀过程中将土中物质带入溶洞中,在上覆粘性土层中形成"土洞",一旦塌陷至地表,就有可能成为灾害。

Study on the Application of Integrated Geophysical Survey to Karst Collapse in Beijing

In recent years, ground collapse had occurred many times in Xiangshan Puandian Town, Haidian District, Beijing, which seriously threatens the safety of the lives and property of the local villagers. In order to find out the causes of ground collapse, the rst step is to search the hidden underground cavity. In the exploration area, the integrated geophysical survey of high-density resistivity method and cross-hole electromagnetic CT had been used, two underground cavities had been successfully detected and then veri ed as karst by the drilling. Comprehensive analysis shows that: the bedrock of the exploration is limestone, which belongs to the soluble carbonate rock; the level of groundwater is in the vicinity of the bedrock surface, and the height of the bedrock surface changes greatly, substances in the soil had been brought into the cave in the long corroding process, formed "soil cave" in the overlying clayey soil layer; once collapsed to the ground surface, it may become a disaster.