瞬变电磁雷达探测盾构管片背后接触状态的模拟试验研究

Model Test of Detection of Contact Status behind Shield Tunnel Segment Using Transient Electromagnetic Radar

盾构管片背后脱空会给隧道后期运营留下安全隐患,而目前的检测技术在检测精度和图像识别等方面仍有一定缺陷。针对地铁隧道中盾构管片背后接触状态的检测,基于瞬变电磁法(TEM)原理,研制了一种通过探测视电阻率变化规律进行判断的雷达采集系统——瞬变电磁雷达(TER)。为验证仪器应用的有效性,首先利用时间域瞬变电磁法视电阻率的计算,研究视电阻率在管片背后接触状态检测中的变化规律;然后通过现场模型试验,探索TER视电阻率的变化特征,并将试验结果与理论计算结果进行对比分析,验证了瞬变电磁雷达探测的有效性;最后在厦门地铁2号线实际测试中取得了良好效果,进一步证实了TER的可行性。TER的成功研发为隧道病害检测提出了新方法和新思路。

Cavities behind shield tunnel segment could create potential safety hazard in operational phase of the tunnel.However,current detection technology still has some defects in detection precision and image identification.Based on the principle of Transient Electromagnetic method(TEM),this paper introduced the Transient Electromagnetic Radar(TER),which was developed to detect the contact status behind tunnel segment for subway tunnel inspection.To verify the effectiveness of using TER,the change rule of apparent resistivity in the detection of contact status behind tunnel segment was calculated by the time domain TEM at first.Then,the change feature of apparent resistivity was summarized and analyzed by model test.Through comparison of the experimental results with theoretical results,the effectiveness of TER was demonstrated.Furthermore,TER was used in the project of Xiamen subway line 2 and obtained good results,which further verified its feasibility.The development and application of TER opened up a new field for the application of TEM and proposed a new idea for detection of tunnel lining segment.