综合物探技术在城市轨道交通勘察中的应用

Application of comprehensive geophysical prospecting technology in urban rail transit survey

在城市轨道交通工程中,为了更加准确地查明破碎带和岩溶的发育情况,采用钻探与高密度电法、瞬变电磁法相结合的方法,对破碎带和岩溶发育区域进行探测。其中高密度电法对工程场地的破碎带和岩溶发育区进行探测,初步判断破碎带和岩溶发育区域的分布范围;瞬变电磁法对岩溶发育区进行探测,钻探用来揭露破碎带和岩溶发育的具体数据;最后对钻探成果和物探成果进行综合分析,得出较为可靠的破碎带和岩溶发育范围。以徐州市城市轨道交通某车站为例,采用综合物探方法,对该场地的破碎带和岩溶的空间分布和规模进行探测。结果表明,高密度电法对确定破碎带和岩溶发育情况具有良好的效果,但是测线布置易受工程场地限制,导致探测深度不足;瞬变电磁法对确定岩溶发育情况效果良好。经钻探资料验证,显示综合物探方法的探测效果良好、成果可靠。

In urban rail transit engineering,in order to find out the development of fracture zone and karst more accurately,the method of combining drilling with high-density electrical method and transient electromagnetic method is used to detect the developed fracture zone and karst.The results show that the most reliable exploration results are obtained for the development of karst fracture zone,and the exploration results of karst fracture zone are the most reliable.Taking a station of Xuzhou urban rail transit as an example,the spatial distribution and scale of fracture zone and karst in the site are detected by comprehensive geophysical method.The results show that the high-density electrical method has a good effect on determining the fracture zone and karst development,but the survey line layout is easy to be limited by the engineering site,resulting in insufficient detection depth;the transient electromagnetic method is effective in determining the development of karst.It is proved by drilling data that the detection effect of the integrated geophysical method is good and the results are reliable.