超大型基坑与地下隧道群相互影响研究  

Research on the interaction between super large foundation pit and underground tunnel group

作　　者：徐剑敏 XU Jianmin(Shenzhen Metro Construction Group Company Limited,Shenzhen,Guangdong 518026,China)

机构地区：[1]深圳地铁建设集团有限公司,广东深圳518026

出　　处：《河北工业科技》2023年第6期445-451,共7页Hebei Journal of Industrial Science and Technology

基　　金：国家重点研发计划(2018YFB2100906)。

摘　　要：为了解决城市复杂地下结构群之间相互影响的工程难题,依托深圳某预建商业建筑基坑和地下规划交通隧道工程,对基坑与隧道群相互影响力学行为以及考虑建筑附加荷载作用下下穿隧道管片配筋设计进行研究。采用有限元计算软件建立基坑与规划交通隧道群三维数值模型和高铁隧道管片配筋荷载-结构模型,分析管片内力、基坑结构位移等指标,评价基坑与地下隧道群的相互影响。结果表明:1)在现有基坑桩-筏板基础结构设计情况下,管片内力变化幅度最大为10.85%,对后期交通隧道近接建筑基坑的影响较小;2)地下规划交通隧道施工过程中对基坑结构位移影响有限,隧道开挖后桩基础最大水平位移为1.36 mm,竖向沉降为2.44 mm,筏板基础最大水平位移为0.41 mm,竖向沉降为2.40 mm;3)在建筑附加荷载作用下,隧道管片最大内力出现在拱顶内侧和拱腰外侧,考虑弯矩传递系数ξ时隧道管片配筋需要加强。研究成果优化了既有桩基础影响下的隧道结构配筋,可以为城市复杂隧道群的设计与施工提供参考。To solve the engineering problem of the corresponding impact between complex urban underground structures,based on a pre built commercial building foundation pit and an underground planned traffic tunnel project in Shenzhen,the mechanical behavior of the interaction between the foundation pit and the tunnel group was studied,as well as the reinforcement design of the underpass tunnel segment under the consideration of additional building loads.A three-dimensional numerical model of the foundation pit and planned traffic tunnel group and a load-structure model for the reinforcement of high-speed railway tunnel segments were established by using finite element calculation software.The internal forces of the segments,displacement of the foundation pit structure,and other indicators were analyzed to evaluate the mutual influence between the foundation pit and the underground tunnel group.The research results indicate that:1)under the existing design of foundation pit pile raft foundation structure,the maximum variation in internal force of the pipe segment is 10.85%,which has little impact on the adjacent building foundation pit of the later traffic tunnel;2)during the construction of the underground planned traffic tunnel,the influence on the displacement of the foundation pit structure is limited.After the tunnel excavation,the maximum horizontal displacement of the pile foundation is 1.36 mm,the vertical settlement is 2.44 mm,the maximum horizontal displacement of the raft foundation is 0.41 mm,and the vertical settlement is 2.40 mm;3)under the additional load of the building,the maximum internal force of the tunnel segment occurs on the inner side of the arch crown and the outer side of the arch waist,considering the moment transfer coefficientξ,the reinforcement of tunnel segments needs to be strengthened.The impact of new tunnels on existing foundation pits are analyzed,and the reinforcement of tunnel structures under the influence of existing pile foundations is optimized in the research,which can provide ref

关 键 词：地下工程 超大基坑 隧道群 近接施工 管片配筋设计 

分 类 号：U45[建筑科学—桥梁与隧道工程]