浅层地震及地质雷达在地铁工程勘察中的应用

Application of Shallow Seismic and Ground Penetrating Radar to Subway Engineering Investigation

为了提高地铁工程勘察的施工效率和准确性,根据地铁工程浅层地表良好的物性条件,基于地震法与地质雷达法探测的高分辨力,采用浅层地震发射波法、瑞雷波法和地质雷达法多种方法进行联合探测;在地铁工程沿线选取典型地段进行探测试验,初步查明典型地段的主要地层分布状况及主要地质构造;利用联合探测成果选取合适位置布设钻孔,指导钻探施工并减少其工作量;通过物探与钻探技术结合,综合解释分析探测段工程地质状况,提高联合探测的准确度及施工效率。探测试验结果表明:通过综合物探,基本查明了探测段地下30 m内岩土层电性分层、速度分层情况以及电性异常区;地震法能够快速地对地表浅层进行层位划分,地质雷达能够准确地查找浅部地质构造;利用成果叠加图结合钻探进行工程地质综合分析,提高了工程勘察的准确性。

In order to improve the construction efficiency and accuracy of metro engineering survey,according to the good physical properties of shallow surface of metro engineering,and based on the high resolution of seismic method and geological radar method,shallow seismic launching method,Rayleigh wave method and geological radar method are used for joint detection;the main stratum distribution and main geological structure of the typical section are preliminarily ascertained through the detection test in the typical section along the metro project.Using the results of joint exploration,the appropriate locations of drilling holes are selected to guide drilling construction and reduce its workload.Through the combination of geophysical prospecting and drilling technology,the engineering geological conditions of the exploration section are comprehensively interpreted and analyzed,so as to improve the accuracy and construction efficiency of the joint exploration.The test results show:through comprehensive geophysical prospecting,the electrical stratification,velocity stratification and electrical anomaly area of rock and soil layers within 30 m underground of the detection section are basically identified;seismic method can quickly divide the shallow layer of the surface,and geological radar can accurately find the shallow geological structure.The accuracy of engineering investigation is improved by comprehensive analysis of engineering geology based on superimposed drawings and drilling.