隧道衬砌背后积水地质雷达检测模型试验研究  

Model Test of GPR Detection on Ponding behind Tunnel Lining

作　　者：杨艳青[1,2] 高永涛[1] 贺少辉[2] 齐法琳[2,3] 

机构地区：[1]北京科技大学土木与环境工程学院,北京100083 [2]北京交通大学土木建筑工程学院,北京100044 [3]中国铁道科学研究院基础设施检测研究所,北京100081

出　　处：《中国铁道科学》2014年第6期63-69,共7页China Railway Science

基　　金：铁道部科技研究开发计划项目(2008G017-A)

摘　　要：制作1∶1大比例尺的铁路隧道整体式衬砌试件,进行地质雷达检测室内模型试验,研究隧道衬砌背后有空洞、积水2种状况下地质雷达图的典型特征,并定量分析积水区域的衬砌厚度、积水厚度;通过对衬砌背后空洞和积水2种试验工况进行地质雷达图数值模拟,对模型试验的结果进行验证。研究结果表明:隧道衬砌背后积水时,地质雷达扫描图上出现明显异常,衬砌外表面界面出现强反射区,其后向围岩内部方向有一段衰减过程,最后才交替出现显著的强弱反射;采用单波分析法可较容易地将空洞与积水2种状况进行区分;衬砌背后积水厚度检测值的计算方法可采用衬砌厚度检测值的计算方法,且计算精度较好;通过对地质雷达扫描图定性分析可初步判断衬砌背后是否存在积水,再结合定量分析可确定衬砌背后积水的范围;试验状况数值模拟结果验证了模型试验结果分析的正确性和合理性。模型试验结果有助于实际工程中对隧道衬砌背后积水的识别。The 1 ＂ 1 large-scale specimen of the integral railway tunnel lining was made. The typical features of the GPR scan under the two situations when there was cavity or ponding behind tunnel lining were studied through indoor model test. Meanwhile, the thickness of the lining and ponding was quantita- tively analyzed. The model test results were verified by the GPR numerical simulation of the two test con- ditions when there was cavity and ponding behind the lining. The results show that when there is ponding behind tunnel lining, obvious abnormalities can be reflected in the GPR scan, with strong reflection zone on the lining surface. Then a significant alternating strength of the reflection appears after a decay process towards the internal surrounding rock. Both cavity and ponding can be differentiated easily be means of single wave analysis method. The way for calculating the detection value of the ponding depth behind the lining is the same as the way for calculating lining thickness, and the calculation accuracy is higher. It can be determined preliminarily whether there is ponding behind the lining by the qualitative analysis for the GPR scan, and the ponding range can be confirmed by combining with the quantitative analysis. The correctness and rationality of model test results is verified by numerical simulation of the test situations. The model test results contribute to the identification of the ponding behind tunnel lining in practical engineering.

关 键 词：隧道工程 衬砌 空洞 积水 地质雷达检测 定量解释 模型试验 

分 类 号：U457[建筑科学—桥梁与隧道工程]