基于移动三维激光扫描的地铁隧道渗漏水检测及致灾因子分析

Leakage Detection and Disaster Factor Analysis of Subway Tunnel Based on Mobile 3D Laser Scanning

地铁隧道渗漏水对结构的可靠性构成较大危害,揭示渗漏水病害的成因、对渗漏水病害进行高效精准诊断是维护地铁安全运营的关键。结合渗漏水发生场景、地质条件和工法等因素,可进行渗漏水病害成因分析。在渗漏水检测方面移动三维激光扫描可快速重构地铁隧道衬砌表面,适合渗漏水的检测。文章以深圳地铁2号线某盾构隧道区间渗漏水诊断为研究案例,采集隧道衬砌管片全域激光点云数据,然后将点云数据依据反射强度转化为灰度图。通过分析灰度图像确定渗漏水主要发生在管片接缝、裂缝和螺栓处。研究发现导致渗漏水的原因主要为材料质量和周边施工扰动,因此地铁建设期做好质量控制是预防渗漏水病害的关键。

The leakage of subway tunnel does great harm to the reliability of the structure.Investigating the causes of leakage,as well as efficient and accurate diagnosis of water leakage is the key to maintaining the safe operations of metro.The analysis of the causes of water seepage can be carried out by taking into account the occurrence of water seepage scenarios,geological conditions and construction methods.Mobile 3D laser scanning can quickly reconstruct the surface of metro tunnel linings and is suitable for water leakage detection.In this paper,a shield tunnel interval of Shenzhen Metro Line 2 is used as a case study for water leakage diagnosis.The laser point cloud data of the tunnel lining was collected and then they were transformed into a greyscale image based on the reflection intensity.It was found from the grey-scale image that water leakage occurred mainly at the joints,cracks and bolts of the pipe sheet.We believed that the main causes of water leakage were material quality and surrounding construction disturbances.Therefore,quality control during the construction period of the metro is the key to preventing water leakage.