地铁车站膨胀土明挖深基坑主体结构免换撑施工技术  

Construction Technology of Main Structure of Deep Foundation Pit in Expansive Soil Excavation Without Changing Bracing

作　　者：陈淼 Chen Miao(Urban Rail Transit Engineering Branch Co.,Ltd.of CTCE Group,Hefei,China)

机构地区：[1]中铁四局集团有限公司城市轨道交通工程分公司,安徽合肥

出　　处：《科学技术创新》2023年第12期187-190,共4页Scientific and Technological Innovation

摘　　要：本研究主要探究了免换撑施工技术在某地铁车站明挖深基坑主体结构中的应用。首先介绍了免换撑施工流程,并结合第三道支撑的结构特点,设计了4种免换撑拆除方案。使用FLAC3D软件构建了深基坑模型,并模拟四种拆撑方案,选择地表沉降、桩体位移和支撑轴力3项指标,对比四种免换撑方案的应用效果。结果表明,方案二“双撑换单撑”的应用效果较好,并将该方案应用到膨胀土明挖深基坑施工中。在深基坑中选择一处试验段,布置轴力计监测整个施工期间的支撑轴力。实测值与计算值接近,并且监测结果均在控制标准以内,符合施工要求。This research mainly explores the application of the brace free construction technology in the main structure of open deep foundation pit of a subway station.This paper first introduces the construction process of no-change brace,and combined with the structural characteristics of the third brace,design four no-change brace removal schemes.FLAC3D software was used to build a deep foundation pit model,and four kinds of debuttoning schemes were simulated.Three indexes of surface settlement,pile displacement and supporting axial force were selected to compare the application effects of four kinds of no-change bracing schemes.The results show that the application effect of scheme 2"double brace for single brace"is good,and this scheme is applied to the construction of expansive soil open deep foundation pit.A test section is selected in the deep foundation pit and axial force meter is arranged to monitor the supporting axial force during the whole construction period.The measured value is close to the calculated value,and the monitoring results are within the control standard,in line with the construction requirements.

关 键 词：明挖深基坑 免换撑技术 地表沉降 支撑轴力 

分 类 号：TU753[建筑科学—建筑技术科学]