地铁车站深大圆形基坑分区开挖变形特征及优化设计研究  

Deformation Characteristics and Optimization Design of Deep and Large Circular Foundation Pit Partitions in Subway Stations

作　　者：曹诗定 唐伟 王志欣 CAO Shiding;TANG Wei;WANG Zhixin

机构地区：[1]深圳市综合交通与市政工程设计研究总院有限公司,广东深圳518003

出　　处：《上海公路》2025年第1期84-92,M0006,共10页Shanghai Highways

摘　　要：为深入探究深大圆形基坑分区开挖的变形规律,揭示开挖过程中的支护变形和受力演化规律,以某城市地铁车站基坑为研究背景,采用有限元数值模拟,从深大圆形基坑分步、不同区域同步开挖这两方面,设计了分区域分步开挖和分区域同步开挖两种开挖方式,并研究了分区开挖步序对基坑变形和支护的影响。研究表明,圆形基坑围护结构具有较小且均匀的变形特性,“拱顶效应”对其变形有一定的约束作用。在基坑开挖过程中,各层的支撑轴力在早期阶段会迅速增加,随着开挖的深入,轴力的增长速度又会逐渐减缓。这种变化趋势表明,基坑开挖对支撑系统的负荷影响显著,初期负荷增加较快,而后期则趋于平稳。在相同的约束条件下,底层支撑的轴力通常大于上层支撑的轴力。在基坑分区分步开挖过程中,应优先选择对称开挖工法,以减少对基坑结构的影响,先进行规模较小的区域开挖,以确保稳定性。This study explores the deformation patterns of zoned excavation in deep circular foundation pits,focusing on the deformation and stress evolution of supporting structures.Using a city subway station pit as the research background,finite element numerical simulations were conducted.The study examines two excavation methods:zoned sequential and synchronized zoned excavation.The results show that circular foundation pits have small and uniform deformation,with the"arching effect"providing some constraint.During excavation,axial forces in the support system increase rapidly at first and then slow down.For zoned sequential excavation,priority should be given to symmetrical excavation sequences to minimize structural impact,with smaller-scale zones excavated first to ensure stability.

关 键 词：基坑工程 圆形深大基坑 变形机制 分区域开挖 优化设计 现场监测 

分 类 号：TU7[建筑科学—建筑技术科学]