利用探地雷达时距曲线求取介质介电常数及其应用

Using the GPR time-distance curve to calculate the dielectric constant and its application

从探地雷达的工作方法出发,遵从射线追踪的原理,设计不同地质结构模型,分析介质介电常数及目标体埋深对探地雷达时距曲线的影响,并提出一种利用时距曲线求取介质介电常数的方法。通过对上海陆家嘴地区探地雷达剖面进行介电常数的提取,分析其分布规律并采用提取结果校正雷达剖面异常体的埋深。结果显示,此法能提高探地雷达时深转换精度,在管线探测、浅部地质结构调查、地下建(构)筑物探测、地质灾害调查、水土污染调查等方面具有一定的应用前景。

Starting at the working mechanism of the ground penetrating radar(GPR),and based on the principle of ray tracing,we designed various geological models and analyzed the GPR time-distance curve with various dielectric constants and depths.Then,we proposed a method for calculating the dielectric constant by using the T-D curve.Subsequently,we extracted the dielectric constant of the GPR section in the Lujiazui area of Shanghai,explored its distribution rule,and extracted the results to correct the depth of the radar profile of the abnormal body.The results show that this method can improve the time-depth conversion accuracy of the GPR.It has potential for application in pipeline detection,shallow geological structure investigation,underground building detection,geological hazard investigation,soil and water pollution investigation,etc.