盾构管片壁后注浆密实度地质雷达正演模拟与实例分析

Forward Modeling and Measured Data Analysis of Grouting Compactness Behind Shield Pipe Segment Wall

根据盾构工法隧道的施工工艺及结构类型,利用GPRMAX3.0软件建立管片壁后存在有不同类型注浆缺陷的3D盾构隧道地质模型,运用有限差分方法正演模拟其缺陷的反射特征,再与实际管片注浆地质雷达检测结果对比分析。结果表明:管片背后注浆不密实区域形状及体积的大小会有不同的反射特征。GPRMAX正演的结果特征与实际地质雷达检测图像较为一致,通过模型正演模拟地质雷达在盾构隧道检测结果是可行的,可以为地质雷达在盾构隧道检测结果的解释提供一定的指导作用。

According to the construction technology and structure type of shield tunnel,using Gprmax3.0 software establish 3 D geological model of shield tunnel with different types of grouting defects behind segment wall,the finite difference method is used to simulate the reflection characteristics of defects,comparative analysis of the results of geological radar detection with actual segment grouting.The results show that:the shape and volume of the non-dense grouting area behind the pipe slice will have different reflection characteristics,the results of GPRMax forward modeling are consistent with the actual geological radar detection images,it is feasible to simulate the detection result of GPR in shield tunnel by model forward modeling,it can provide some guidance for the interpretation of the detection results of the geological radar in the shield tunnel.