地铁车站盾构接收区近接既有建筑物超宽扩挖施工技术  

Construction Technology for Ultra-wide Excavation near Existing Buildings in Metro Station Shield Tunneling Receiving Area

作　　者：潘伍 PAN Wu(China Railway Tunnel Group Co.,Ltd.,530007,Nanning,China)

机构地区：[1]中铁隧道局集团建设有限公司,南宁530007

出　　处：《城市轨道交通研究》2024年第8期149-154,160,共7页Urban Mass Transit

基　　金：中铁隧道局集团有限公司科技创新计划项目(遂研合2019-35)。

摘　　要：[目的]为解决地铁车站超大断面下穿扩挖施工引起的地面既有建筑物沉降控制困难的问题。[方法]依托成都地铁新建18号线倪家桥站盾构接收区下穿既有立交桥引桥工程,通过数值模拟分析方法,开展了地铁车站盾构接收区近接既有建筑物超宽扩挖施工技术研究,并采用现场监测数据进行了验证。[结果及结论]采用超前大管棚、12导洞分部扩挖法以及复合式衬砌等施工技术,能够在有效控制既有建筑物沉降的前提下,实现车站主体结构长距离扩挖,保证车站盾构接收区结构的吊装净空;对既有建筑物沉降变形造成主要影响的施工步骤是①、⑦导洞围护桩的破除,以及①、⑦导洞的开挖;既有建筑物在①、④导洞处沉降明显,最大沉降值为8.82 mm,是模拟结果沉降最大值的1.21倍;实测结果与模拟结果均满足安全控制要求。[Objective]It is aimed to address the difficulty in settlement control of existing ground buildings during ultra-large section excavation beneath them in metro station construction.[Method]Based on the shield tunneling receiving area project of newly built Chengdu Metro Line 18 Nijiaqiao Station,which passes under an existing overpass approach bridge,numerical simulation analysis is conducted to study the construction technology of ultra-wide expansion excavation near existing buildings,and field monitoring data is used for verification.[Result&Conclusion]The use of advanced pipe-roofing,12-pilot tunnel segmented expansion excavation,and composite lining construction techniques can effectively control the settlement of existing buildings while enabling long-distance expansion of the main station structure and ensuring the hoisting clearance for shield machine reception.The primary construction steps affecting the settlement deformation of existing buildings are the removal of protective piles and the excavation of①and⑦pilot tunnels.Significant settlement is observed at①and④pilot tunnels,with the maximum settlement value reaching 8.82 mm,which is 1.21 times the maximum settlement value obtained from the simulation.Both the measured and simulated results meet the safety control requirements.

关 键 词：地铁车站 盾构接收区 下穿建筑物 超宽扩挖施工技术 

分 类 号：U231.3[交通运输工程—道路与铁道工程]