管线位置对地下空洞检测的影响

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。制作实验装置,测量单独的空洞模型,分析产生的波形图,初步了解了空洞在反射波谱上的图像特征。将管线埋设于不同位置,对比它们与单独空洞模型所得到的反射波形之间的图像差异,研究其对地下空洞探测结果的影响规律。结果表明,管线水平位置的不同、管线和空洞间距的不同都会对电磁波的传播造成影响,主要在于阻碍空洞反射波传播地表,不利于判断空洞位置和计算脱空大小。本次研究所得图像可作为样本,为现场测量和危害评估提供理论支持,对于防范塌陷灾害有一定的促进作用。

The impact of pipeline position on the underground cavity detection

Through analyzing the electromagnetic wave propagation in underground medium, this paper introduces the basic principle of detecting the underground cavity by GPR(Ground Penetrating Radar). A single cavity model is established in the experimental device and the characteristics of the reflection spectrum about the underground cavity can be understood preliminarily by analyzing the detecting waveform. Establish models of pipelines buried in different position. Contrast the differences of the reflection waveform between these models and that of a single cavity and study the impact on the underground cavity detection. The study shows that the horizontal position of pipeline and the distance between pipeline and cavity has affected the electromagnetic wave propagation. It prevents the reflection wave from transmitting back to the ground so that the position and the size of the underground cavity cannot be identified precisely. The waveform in this study can be collected as samples. It provides theoretical support for the detection and the damage assessment, and is very effective in preventing collapse.