第1期研究报告软土地区邻近既有建筑半盖挖深基坑变形特征徐健1周子涵2王林枫2周小涵2(1．南京地铁建设有限责任公司，210005，南京;2．重庆大学土木工程学院，400045，重庆∥第一作者，高级工程师)摘要为研究邻近既有建筑的半盖挖深基坑变形特性及环境效应，以南京地铁5号线山西路站的软土地区半盖挖深基坑工程为例，将基础形式、支护形式等作为变量，设计了8种数值模拟工况进行分析。研究结果表明:既有建筑使基坑一侧产生偏压导致地连墙侧移曲线整体向基坑内移动，盖板与地连墙的刚性连接使其顶部发生翘曲，地连墙嵌入岩层限制了底部侧移量，改变了地连墙下端侧移曲线形状;坑外地面沉降曲线受建筑及基础形式影响较大，受盖板和地连墙深度影响较小;基坑开挖主要影响墙后2倍深度以内三角形区域的土体沉降，既有建筑地下室和桩基础能有效控制建筑靠近基坑一侧土体的沉降大小及范围。关键词地铁;软土地区;半盖挖施工;深基坑变形中图分类号TU447…TU433DOI:10．16037/j．1007－869x．2023．01．014DeformationCharacteristicsofSemi-coveredDeepFoundationPitAdjacenttoExistingBuildingsinSoftSoilAreaXUJian，ZHOUZihan，WANGLinfeng，ZHOUXiao-hanAbstractTostudythedeformationcharacteristicsandenvi-ronmentalimpactofsemi-covereddeepfoundationpitadjacenttoexistingbuildings，takingthefoundationpitengineeringinsoftsoilareaofNanjingMetroLine5ShanxiＲoadStationasexample，andadoptingfoundationformandsupportformasvariables，8groupsofnumericalsimulationworkingconditionsaredesignedandanalysed．Ｒesearchresultsshowthatexistingbuildingscauseeccentricloadsononesideofthefoundationpit，leadingtotheoverallmovementofdiaphragmwalllateralcurveintothepit．Therigidconnectionbetweencoverplateanddiaphragmwallmakesthewalltopwarp，andtheembedmentofdiaphragmwallsintorockstratumlimitsthelateralmovementofthebottomandchangestheshapeofdiaphragmwallbottomlateralcurve．Thelandsubsidencecurveoutsidethepitisgreatlyinfluencedbytheformofbuildinganditsfoundation，andhaslittlerelationwithcoverplateanddepthofdiaphragmwalls．Thefoundationpitexcavationmainlyaffectssoilsettlementinthetriangularareawithin2timesofdepthbe-hindthewall，andtheexistingbuildingbasementandpilefoundationcaneffectivelycon...
