城市地铁车站深大基坑分区开挖顺序优化研究  

Optimisation of Zoned Excavation Sequence of Deep and Large Foundation Pit in Urban Metro Station

作　　者：刘锐 方成成 储朱敏 李猛 LIU Rui;FANG Chengcheng;CHU Zhumin;LI Meng(Urban Rail Transit Engineering Branch Co.,Ltd.of CTCE Group,Hefei 230022,Anhui,China)

机构地区：[1]中铁四局集团有限公司城市轨道交通分公司,安徽合肥230022

出　　处：《隧道建设（中英文）》2023年第S02期513-522,共10页Tunnel Construction

摘　　要：对于由不同形状组成的深大基坑工程,开挖的顺序会对基坑及其围护结构的变形产生较大的影响。为了确定深大基坑不同开挖顺序对施工稳定性的影响并得出最佳开挖顺序,依托福州地铁船政文化城站基坑工程,应用有限元软件,针对由圆形和条形组成的基坑工程,对不同分部开挖的方案进行数值模拟计算,得出不同开挖顺序下基坑附近的地表沉降及围护结构变形规律,得出结论:1)对于小里程基坑,先开挖条形基坑再开挖圆形基坑的顺序造成的小里程基坑外的地表沉降大于先开挖圆形基坑再开挖条形基坑,而对于圆形基坑和大里程基坑,先开挖条形基坑再开挖圆形基坑顺序更优;2)先开挖条形基坑再开挖圆形基坑所造成的边墙最大水平位移要小于先开挖圆形基坑再开挖条形基坑;3)对于圆形基坑部分的开挖,盖挖优于明挖,保留核心土的开挖顺序更优。总体来看,采用先开挖条形基坑后开挖圆形基坑,且圆形基坑采用盖挖保留核心土的开挖方式为更优方案。For deep and large pits composed of different shapes,the excavation sequence significantly influences the deformation of the foundation pit and its supporting structures.To minimize the impact of different excavation sequences on construction stability and determine the optimal sequence,numerical simulations are conducted using finite element software based on the Fuzhou Metro Foochow Arsenal Station excavation project.Circular and rectangular sections are considered,and various excavation sequences are simulated.The following conclusions are drawn:(1)For small-span pits,excavating the rectangular section first and then the circular section results in larger surface settlements compared to excavating the circular section first,whereas for circular and large-span pits,excavating the rectangular section first and then the circular section is more favorable.(2)Excavating the rectangular section first and then the circular section leads to smaller maximum horizontal displacements of the sidewalls compared to the reverse sequence.(3)For the circular section,cut and cover excavation is superior to open cut excavation,and preserving the core soil during excavation is the optimal method.In summary,excavating the rectangular section first and then the circular section,with the circular section excavated using cut and cover excavation while preserving the core soil,represents the optimal approach.

关 键 词：地铁车站 深大基坑 条形基坑 圆形基坑 开挖顺序 数值模拟 

分 类 号：U45[建筑科学—桥梁与隧道工程]