地质雷达检测隧道衬砌周围积水的试验研究

Experimental study on the detection of water accumulation around tunnel lining by GPR

隧道衬砌周围积水对隧道工程安全运营有严重的威胁,目前地质雷达多用于对隧道衬砌检测,极少利用其对隧道衬砌后积水进行检测。从确保隧道运营安全的需要出发,进行了地质雷达现场模拟检测试验,研究隧道衬砌周围无积水、局部积水与完全积水3种状况下地质雷达波的典型特征,探讨采用地质雷达对隧道衬砌后积水进行检测的方法。结果表明:雷达波在相对均匀的无水介质中传播时,波的频率及波幅未发生明显的变化,呈现自然衰减的趋势,而雷达波在有积水的围岩土体介质中传播时,波的频率和振幅均发生了较大变化,通过对雷达波形的分析,可有效检测出隧道衬砌后有无积水及其范围,采用地质雷达检测隧道衬砌后积水的方法切实可行。

The accumulation of water around the tunnel lining poses a serious threat to the safe operation of tunnel engineering.At present,the geological radar is mostly used to detect the tunnel lining,yet it is rarely used to detect the accumulation of water after the tunnel lining.Starting from the need to ensure the safety of tunnel operation,this paper carried out a geological radar field simulation detection to study the typical characteristics of geological radar waves in the three conditions of no accumulation of water around the tunnel lining,partial accumulation of water,and complete accumulation of water.This article discusses the method of using geological radar to detect the accumulated water after the tunnel lining.The results show that when the radar wave propagates in a relatively uniform anhydrous medium,the frequency and amplitude of the wave do not change significantly,showing a natural attenuation trend.However,when the radar wave propagates in the surrounding rock and soil medium with water,the frequency and amplitude of the wave have changed significantly.Through the analysis of the radar waveform,the presence and scope of the accumulated water after the tunnel lining can be effectively detected.The method of using the ground penetrating radar to detect the accumulated water after the tunnel lining is feasible.