探地雷达在南京地铁隧道工程检测中的应用

The application of ground penetrating radar to subway tunnel engineering testing in Nanjing

溶洞是地铁隧道工程的重要检测内容之一,探地雷达波在溶洞中传播的信号特征与围岩存在明显的差别,雷达反射波组的振幅、波长和频率会随着介质的电性变化而改变,正确识别溶洞的雷达波组特征是判别溶洞存在及其性质的关键所在。以南京地铁三号线滨江路站—五塘村站之间地铁隧道下方岩体内隐含溶洞探测为例,着重讨论了溶洞在探地雷达检测剖面上的波形显示特征,结合钻孔验证,说明探地雷达技术在城市地铁隧道工程溶洞探测中是有效的和实用的。

Karst detection is one of the important detection tasks in subway construction. Signal propagating characteristics of ground penetrating radar in the cave and in the rock show significant differences. The amplitude, wavelength and frequency of the radar wave change with the electrical properties of the media, and hence correct identification of radar wave group characteristics of karst cave is the key to identifying caves and their properties. This paper deals with the implication of karst detection in Nanjing Metro Line between the Binjiang Road Station and Wutang Village Road Station,with emphasis placed on the waveform display characteristics of the karst cave on the ground-penetrating radar detection. In combination with drilling verification, the authors hold that the ground penetrating ra- dar is effective in detecting the karst in the city subway tunnel.