地质雷达在铁路隧道工程质量检测中的应用

Application and Analysis of GPR in Railway Tunnel Engineering Quality Inspection

针对铁路隧道施工中可能出现的质量问题,利用地质雷达技术进行隧道工程质量检测。岩土工程介质的电磁学特性决定了应用地质雷达的效果,介质的电磁学性质可用介电常数、磁导率和电导率3个参数来表征。地质雷达技术探测是一种利用广谱电磁波确定不同介质分布的探测方法。针对铁路隧道,给出地质雷达在无损检测应用中的工作方法,包括测线布置、采集参数设定、现场检测和后期资料处理解释。通过对现场数据处理分析,可以精确探测衬砌厚度,确定钢筋及格栅钢架的分布位置及数量,查明衬砌背后特别是拱顶存在的空洞和回填不密实区域。使用地质雷达对隧道混凝土衬砌结构进行检测,实践证明技术方法是切实可行的。

GPR （Ground Penetrating Radar） can be applied to tunnel engineering quality inspection to detect some quality problems possibly existed in railway tunnel construction. The electromagnetic characteristics of the geotechnical engineering medium decide the effects of GPR application. The electromagnetic characteristics of the medium can be illustrated by dielectric constant, permeability and conductivity. GPR detection is a method using broad-spectrum electromagnetic wave to determine the distribution of different medium. Aiming at railway tunnel, the methods of applying GPR to non-destructive inspection have been given, which include measuring line distribution, acquisition parameters setting, field inspection and the follow-up data interpretation. By processing and analyzing field data, the following functions can be performed, such as detecting the thickness of concrete lining accurately, determining the distribution position and quantities of rebar and grid steel, searching existed cavity and uncompacted area behind the lining especially lining arch top. It has been proved that GPR is a feasible method to inspect the structure of tunnel concrete lining.