地铁隧道管片背后脱空及渗水病害检测方法

地铁隧道管片背后的脱空和渗水病害严重威胁地铁的施工和运营安全。针对目前探地雷达技术在管片背后病害检测中仍然存在检测精度低、属性难以划分的问题,开展管片后的脱空和渗水病害检测方法研究。首先,通过搭建多组正演模型,分析管片背后脱空和渗水病害的雷达波反射特征,提出将核匹配追踪算法用于病害识别,提高检测精度;然后,根据回波的波组形态、振幅和相位特性、吸收衰减特性等方面特征,建立地铁隧道管片背后病害属性划分标准,可实现不同种类病害的分级以指导施工修复;最后,对厦门地铁2号线进行探测试验,结果表明:该检测方法可有效实现地铁隧道管片背后病害的快速检测,4条测线共检测出异常区域23处。该方法可为地铁隧道施工及运营安全提供一种有效的检测手段。

Damage Detection Method for Cavity and Water Seepage Behind the Subway Tunnel Segments

The damage of cavity and water seepage behind the subway tunnel segments seriously threaten subway safety during construction and operation.For the damage detection behind the subway tunnel segments based on Ground Penetrating Radar (GPR),this technology still has the problems of low detection accuracy and diff iculty in attribute classif ication .In this paper,how to detect the damages of cavity and water seepage behind the subway tunnel segments was studied.Firstly,a set of forward modeling models were built to analyze the characteristics of the ref lection GPR wave from cavity and water seepage damages.Secondly,a kernel matching pursuit algorithm was proposed for damage identif ication and improving detection accuracy.The criteria for damage attribute classif ication was established according to the ref lection wave shapes,amplitudes and phase characteristics,absorption and attenuation characteristics,etc.In this way,different damages may be classif ied to provide guidance for construction and repair.Finally,a detection experiment was carried out in the Line 2,Xiamen Metro.The results show that the detection method can effectively realize the rapid damage detection behind subway tunnel segments.A total of 23 abnormal regions were detected in the four measuring lines.The method may provide an effective detection technology for the safety of subway tunnel construction and operation.