综合勘察方法在城市地下车站岩溶勘察中的应用

Application of comprehensive survey method in karst exploration of urban underground station

岩溶作为一种典型的不良地质现象,其发育情况和分布特征对工程项目的设计和施工有重要影响。由于岩溶的发育具有极大的随机性和不确定性,仅靠传统的钻探很难准确查清地下岩溶的发育情况。以深圳某轨道交通项目地下车站岩溶勘察为例,采用工程地质调绘、工程地质钻探、等值反磁通瞬变电磁法和跨孔弹性波CT相结合的综合勘察方法,查明了车站范围内岩溶的分布、规模和溶洞充填类型等发育特征,经统计场地内钻孔见洞率41.18%,总线岩溶率为22.40%,岩溶发育等级为强烈发育。各种勘察手段相互配合与验证,取得了良好的勘察成果。

As a typical adverse geological phenomenon,karst has a significant impact on the design and construction of engineering projects.Due to the considerable randomness and uncertainty of the development of karst,it is difficult to accurately determine the development of underground karst by relying solely on traditional engineering geological drilling.Taking the karst survey of an underground station of a rail transit project in Shenzhen as an example,this paper uses comprehensive survey methods based on engineering geological drilling and various geophysical prospecting methods(opposing coils transient electromagnetic method,and cross-hole elastic wave CT),combined with engineering geological survey,borehole wave velocity testing,in-situ testing and other means,to find out the distribution,morphology and scale of karst within the station area.According to the statistics,the hole-seeing rate is as high as 41.18%and the linear karst rate is 22.40%.Therefore the karst development level is strong.With various survey methods supporting and verifying each other,good survey results have been achieved.