北京地铁某明挖深基坑工程测与稳定性数值分析 前沿论文.docVIP

北京地铁某明挖深基坑工程监测与稳定性 数值分析 刘波1,2，杨成淳1，曹波1，张浩1，赵子江1 5 （1. 中国矿业大学（北京） 力学与建筑工程学院，北京 100083； 2. 深部岩土力学与地下工程国家重点实验室，北京 100083） 摘要：以北京地铁十号线二期巴沟盾构始发井深基坑工程为背景，进行了始发井深基坑开挖 过程中支护桩桩体变形、桩侧土压力以及桩身钢筋应力的监测研究。同时，采用 FLAC3D 对 基坑开挖进行全过程动态模拟，分析研究了支护结构整体刚度及龙门吊载荷作用对基坑支护 10 结构受力及变形的影响。综合实测与数值模拟结果表明：数值模拟可较好地预测基坑支护桩 的侧向变形规律，支护结构的最大水平位移多发生在结构中下部。因此在施工过程中要对桩 身变形进行严密的监测，并及时安装钢支撑及浇注混凝土中板，这有利于减小土体侧向位移 及地表沉降, 保证深基坑的施工安全。 关键词：盾构始发井；结构监测；信息化施工；FLAC3D 模拟 15 中图分类号：U451.2 Deformation Monitoring and Numerical Modeling on the Stability of an Open Excavated Foundation-pit in Beijing Metro 20 LIU Bo1,2, YANG Chengchun1, CAO Bo1, ZHANG Hao1, ZHAO Zijiang1 (1. School of mechanics Civil Engineering, China University of Mining Technology, Beijing 100083; 2. State Key Laboratory of Geomechanics and Deep Underground Engineering, Beijing 100083) Abstract: Through the shield-construction origination shaft of Bagou Station of metro line 10 in 25 Beijing, this paper presents the monitoring results of deformation on retaining pile, the lateral soil pressures distribution on the retaining structures and reinforcing steel bar stresses of piles during deep excavation. Meanwhile, the numerical simulation of the whole excavating process with FLAC3D program was established, focusing on the influence of the integral rigidity of enclosure structure and the gantry crane’ s load on the pressure and deformation of enclosure structure. The 30 better agreement of measured data and the numerical simulation shows that the numerical simulation can be used to analyze the actual deformation law of the retaining pile. Further analysis of the results of measured data and numerical simulation can be drawn that the maximum lateral displacement occurs at the middle-lower part of the retaining pile. Therefore rigorous monitoring on the deformation of retaining structures must be adopted. Furthermore it should be in time to 35 assemble steel support and pour concrete floor in order to reduce soil side displacement and ground sur