基于探地雷达和位移反分析的灰岩边坡稳定性数值模拟  

Stability Numerical Simulation of Limestone Slope Based on Ground Penetrating Radar and Displacement Back Analysis

作　　者：温世儒[1] 吴霞[2] WEN Shi-ru;WU Xia(School of Civil and Surveying&Mapping Engineering,Jiangxi University of Science and Technology,Ganzhou Jiangxi 341000,China;School of Architecture Engineering,Jiangxi College of Applied Technology,Ganzhou Jiangxi 341000,China)

机构地区：[1]江西理工大学土木与测绘工程学院,江西赣州341000 [2]江西应用技术职业学院建筑工程学院,江西赣州341000

出　　处：《公路交通科技》2022年第10期40-48,共9页Journal of Highway and Transportation Research and Development

基　　金：国家自然科学基金项目(41272285);江西省教育厅科学技术研究青年项目(GJJ170564);江西省教育厅科学技术研究重点项目(GJJ204903)。

摘　　要：灰岩边坡的整体溶蚀性和风化性具有显著的时空变异性,依据常规规范难以准确有效地获取完整边坡的力学参数,从而导致数值模拟计算结果的可靠性被弱化乃至完全失效,难以为现场施工提供有效的参考信息,对此提出了一种基于探地雷达和位移反分析的边坡力学参数获取方法。以广西宜州-河池高速公路No.2标段某灰岩边坡为依托,采用探地雷达对边坡内部的富水性和破碎性进行了探测并据此将边坡划分为不同级别的单元块,然后在非空腔单元块上安装位移计用于测定单元块的位移值,并据此采用BMP90位移反分析法获取了不同单元块的弹性模量、泊松比和黏聚力等力学参数;基于MIDAS-GTS有限元数值模拟软件建立了完整边坡的网格模型,并分别采用反分析所得不同单元块的力学参数及规范整体赋值对边坡的下滑位移值进行了计算。为了对下滑位移值的数值模拟计算结果进行对比验证,在现场开展了位移同步监测。经与同步现场位移监控量测结果进行对比发现:基于边坡单元块划分及其反分析结果所得数值模拟计算值与监测值较为接近,说明与笼统地根据规范对完整边坡的力学参数进行赋值相比,由该方法所得力学参数与边坡真实值更加吻合。研究内容能为溶蚀地区灰岩边坡的稳定性数值模拟分析提供相关参考。The overall dissolution and weathering of limestone slope have significant temporal and spatial variability, so it is difficult to obtain the mechanical parameters of complete slope accurately and effectively according to conventional specifications, and the reliability of the numerical simulation result would be weaken or even to be completely invalid, and it is difficult to provide effective reference information for field construction. Therefore, a method for obtaining the mechanical parameters of slope based on GPR and displacement back analysis is proposed. On the basis of a limestone slope in No.2 section of Yizhou-Hechi expressway in Guangxi, the water-rich and crushing properties of the slope are detected by GPR,and the slope is divided into different graded units. Then, a displacement gauge is installed on the non-cavity unit block to measure the displacement value of the unit block, and the mechanical parameters such as elastic modulus, poison’s ratio and cohesive force of different unit blocks are obtained by using BMP90 displacement back analysis method accordingly. The grid model of complete slope is established by using MIDAS-GTS finite element numerical simulation software, and the sliding displacement value of the slope is calculated by using the mechanical parameters of different unit blocks obtained by back analysis and the whole assignment of specification. In order to compare and verify the numerical simulation result of the sliding displacement value, the field synchronous monitoring and measurement of the displacement is carried out. Compared with the results of synchronous field displacement monitoring and measurement, it is found that the numerical simulation values based on slope unit division and its back analysis result are close to the monitored values, which indicates that the mechanical parameters obtained by this method are more consistent with the real values of slope than the mechanical parameters of complete slope generally assigned according to the specification. The study can

关 键 词：道路工程 稳定性数值模拟 位移反分析 灰岩边坡 探地雷达 

分 类 号：U412[交通运输工程—道路与铁道工程]