倪建航

摘 要：本文以杭州钱江新城地铁9号线五堡站—六堡站区间基坑工程为依托，利用FLAC 3D软件模拟基坑开挖支护过程，对基坑开挖过程中引起的围岩变形和地表沉降过程进行数值模拟。地铁五堡站—六堡站区间基坑采用明挖法施工，分两层开挖，其中负二层为主要监测位置，两帮采用地下连续墙支护，开挖过程中采用钢筋混凝土梁做支撑。其间利用数值模拟，结合现场监测值，分析基坑开挖过程的变形和支护效果。经验证，数值模拟技术在基坑开挖过程中具有一定的指导性，可以为工程施工提供一定的参考。

关键词：明挖法;地铁区间;基坑开挖支护;FLAC 3D;数值模拟;变形分析

中图分类号：TU753文献标识码：A文章编号：1003-5168（2021）14-0101-04

Abstract： Based on the foundation pit project between Wubao Station and Liubao Station of Hangzhou Qianjiang New City Metro Line 9， the foundation pit excavation and support process was simulated by FLAC 3D software in this paper， and the surrounding rock deformation and surface settlement process caused by the excavation of the foundation pit were numerically simulated. The foundation pits between Wubao Station and Liubao Station of the subway are constructed by the open-cut method and excavated in two layers， among them， the second floor is the main monitoring location， the two sides are supported by underground continuous walls， and reinforced concrete beams are used as support during the excavation process. In the meantime， numerical simulation was used to analyze the deformation and supporting effect of the foundation pit excavation process in combination with the field monitoring value. It has been verified that the numerical simulation technology has certain guidance in the process of foundation pit excavation and can provide a certain reference for engineering construction.

Keywords： open cut method;subway section;foundation pit excavation support;FLAC 3D;numerical simulation;deformation analysis

随着社会的发展和进步，地铁的修建成为加快城市发展的关键，但随着城市规模的不断扩大，地铁修建需求增加，基坑工程量越来越大，其对城市地下围岩和地层的扰动越来越大，岩土层易发生变形、沉降，进而对地表设施产生不利影响。过去，基坑的稳定和变形分析往往是总结工程经验，不能定量地对基坑安全进行评价[1]。数值模拟方法可以有效地模拟基坑开挖过程中产生的岩土危害，可以从多方面综合地考虑岩土变形的因素，从而为工程施工提供一定的参考。吴意谦通过有限元软件建立基坑模型并进行开挖活动，分析了地铁车站基坑开挖过程中的变形规律，以指导现场施工[2];胡安峰等研究某地铁车站开挖过程……