第18卷增刊2地下空间与工程学报Vol.182022年12月ChineseJournalofUndergroundSpaceandEngineeringDec.2022砂卵石地层盾构下穿高速公路加固方案研究方广涛1,方华昌1,涂怀宇2,玄期林1,王卢伟2(1.中交一公局集团有限公司,北京100024;2.西南交通大学土木工程学院,成都610031)摘要:成都地铁17号线九江北站~白佛桥站盾构区间侧穿绕城高速江安立交桥台并下穿高速公路路基,在砂卵石地层中大直径盾构隧道掘进易导致地层沉降,若沉降过大会威胁到高速公路的安全运营,故有必要对盾构隧道洞内加固方案开展研究。采用三维数值方法对隧道洞顶不同范围内的地层进行洞内注浆加固模拟,以高速公路路基沉降、管片内力及邻近桩基水平位移为主要评价指标,研究不同加固方案对地表沉降及邻近桩基横向位移的控制效果。结果表明:(1)当对隧道拱部120°和180°及径向3m范围土体进行注浆加固时,路基沉降及管片内力均满足控制标准要求;(2)各方案加固效果对比发现,增加径向注浆厚度相较于增大环向注浆范围对地表沉降的控制效果更明显;(3)加固前后管片内力均满足控制标准要求;(4)隧道洞内注浆加固对侧穿的桩基变形影响较小,各加固工况下其水平变形均满足控制标准要求。关键词:砂卵石地层;土压平衡盾构;高速公路;下穿;加固方案中图分类号:U25文献标识码:A文章编号:1673-0836(2022)增2-0841-09StudyonReinforcementSchemesofShieldTunnelingthroughHighwayinSandyPebbleStratumFangGuangtao1,FangHuachang1,TuHuaiyu2,XuanQilin1,WangLuwei2(1.CCCCFirstHighwayEngineeringGroupCo.,Ltd.,Beijing,100024,P.R.China;2.SchoolofCivilEngineering,SouthwestJiaotongUniversity,Chengdu610031,P.R.China)Abstract:TheshieldsectionfromJiujiangnorthstationtoBaifoqiaostationofChengdumetroline17passesalongsidetheJiang'anoverpassabutmentoftheringexpresswayandcrossesunderneaththeroadbedoftheringexpressway.Thelarge-diametershieldtunnelinthesandypebblestratumiseasytocausetheformationsettlement.Ifthesettlementistoolarge,itwillthreatenthesafeoperationoftheexpressway.Soitisnecessarytocarryoutresearchonthereinforcementplanoftheshieldtunnel.Thethree-dimensionalnumericalmethodisusedtosimulatethegroutingreinforcementindifferentareasoftheshieldtunnelroof.Thesettlementofthehighwaysubgrade,theinternalforceofthesegmentandthehorizontaldisplacementoft...
