软土地区深基坑工程存在的变形与稳定问题及其控制——基坑变形的控制指标及控制值的若干问题  

Stability and Deformation Problems During Deep Foundation Excavation in Soft Soil Area and Their Control Measures——Allowable Deformation Control and Unconventional Deformation

作　　者：郑刚[1] 焦莹[2] 李竹[2] 

机构地区：[1]天津大学建筑工程学院,天津300072 [2]天津城投建设有限公司,天津300050

出　　处：《施工技术（下半月）》2011年第4期8-14,共7页Construction Technology

基　　金：国家重点基础研究发展计划(973计划)资助项目(2010CB732106)

摘　　要：软土地区的城市深基坑工程设计与施工面临越来越复杂的环境条件,诸如建筑物、道路、地下管线、地下隧道等,确定基坑施工对环境的影响的变形控制要求是一个难问题。根据我国现行有关标准,目前一般采用控制支护结构的最大水平位移。对国内外基坑支护的变形及其环境影响效应控制规定进行了讨论。结合基坑支护结构变形及其相应的影响效应控制指标,分析了影响基坑外土体、建筑物及其他设施变形的影响因素,建议当基坑外存在变形需严格控制的建筑物与设施时,不宜仅按现行规范简单确定围护结构的最大水平位移限值,而应进行专门的变形分析,采取"案例参照、个案分析"的原则。It is becoming more and more difficult to determinate the allowable deformation due to urban area deep foundation excavation when it is surrounded by various buildings,roads,buried pipelines and underground tunnels.According to the current codes,the maximum displacement of retaining wall is the main index to be controlled during design and construction stage.The indexes of deformation of retaining structure and surrounding buildings of domestic and international codes are compared and discussed.Some issues that may affect the deformation of ground behind retaining wall,building and other services are classified.When there are nearby buildings or services that are sensitive to deformation,the allowable maximum deformation of retaining wall is suggested to be determined by detail analysis instead of determined simply according to the current codes.

关 键 词：软土 基坑 变形 水平位移 拉应变 

分 类 号：TU447[建筑科学—岩土工程]