探地雷达检测地下空洞的实验研究

Experimental Study on Underground Cavity Detection By Ground Penetrating Radar

通过分析电磁波在地下介质中的传播规律,介绍了探地雷达检测地下空洞的基本原理。利用时域有限差分方法进行正演模拟,初步了解了空洞在反射波谱上的图像特征。制作实验装置,对比了空洞试验模型在不同实验条件下测量所得到的反射波形之间的图像差异,并进行波速标定,验证探测结果的准确性。通过分析研究,总结出了地下空洞在雷达波谱上的图像识别规律,为现场测量和危害评估提供理论支持,对于防灾减灾有一定的促进作用。

Through analyzing the electromagnetic wave propagation in underground medium, introduce thebasic principle of detecting the underground cavity by GPR(Ground Penetrating Radar). Using FDTD(Finite Difference Time Domain) in the forward simulation, the characteristics of the reflection spectrumabout the cavity can be preliminarily understood. Make an experimental device and establish differentkinds of cavity models. Contrast the differences of the reflection waveform between the different models.Then compare the accuracy of detection results through the wave velocity calibration. The imagerecognition rules of underground cavity in radar spectrum are summarized. It provides theoretical supportfor the detection and the damage assessment, and is very effective in disaster prevention and reduction.