大跨度人防隧道工程下穿施工对既有地铁隧道区间结构稳定性的影响  

Impact of Large-span Civil Defense Tunnel Project Under-passing Construction on Structural Stability of Existing Metro Tunnel Intervals

作　　者：麻凤海[1] 董博 宋帅 杨修猛 MA Fenghai;DONG Bo;SONG Shuai;YANG Xiumeng(College of Engineering and Architecture,Dalian University,116622,Dalian,China;Qingdao Metro Group Co.,Ltd.,266001,Qingdao,China;Beijing Urban Construction Exploration&Surveying Design Research Institute Co.,Ltd.,100101,Beijing,China)

机构地区：[1]大连大学建筑工程学院,大连116622 [2]青岛地铁集团有限公司,青岛266001 [3]北京城建勘测设计研究院有限责任公司,北京100101

出　　处：《城市轨道交通研究》2024年第4期33-39,共7页Urban Mass Transit

基　　金：国家自然科学基金项目(51474045)。

摘　　要：[目的]为分析新建大跨度人防隧道工程小净距下穿既有地铁线路施工时对地铁隧道区间结构稳定性的影响,需对人防隧道下穿施工过程进行模拟研究。[方法]依托青岛某扁平大断面人防隧道下穿既有地铁区间隧道工程,建立了三维有限元模型,模拟人防隧道开挖的全过程。重点分析了人防隧道设置的中隔墙在开挖过程中的力学响应及变形规律,以及整个施工过程对既有地铁车站及其区间隧道的影响情况。[结果及结论]人防隧道中隔墙在先行洞和后行洞施工过程中呈现出明显的偏压趋势;人防隧道初期支护结构受既有地铁隧道的上部拱顶效应与中隔墙的双重作用,呈现出罕见的前大后小的“四象限”分布规律,且右侧沉降值大于左侧沉降值;既有地铁车站及其区间结构受人防隧道开挖空间效应的影响明显,其变形趋势均表现为向开挖侧移动,但其变形值均小于规范规定的预警值。[Objective]To analyze the construction impact of new large-span civil defense tunnel on metro tunnel interval structural stability when under-passing existing metro line with a small clear distance,it is necessary to conduct a simulation study of the civil defense tunnel under-passing construction process.[Method]Leveraging a flat large profile civil defense tunnel under-passing existing metro tunnel interval project in Qingdao,a three-dimensional finite element model is established to simulate the whole process of civil defense tunnel excavation.The mechanical response and deformation patterns of the diaphragm wall set in the civil defense tunnel during excavation is emphatically analyzed,as well as the impact of overall construction process on existing metro station and tunnel interval.[Result&Conclusion]The civil defense tunnel diaphragm wall exhibits a noticeable biasing trend during the construction of both the leading and trailing holes.In the initial support phase of the civil defense tunnel,a rare′four-quadrant′distribution pattern is observed due to the combined effects of the existing metro tunnel upper arching effect and the diaphragm wall,with higher settlement values on the right side compared to the left side.The existing metro stations and interval structures experience a significant impact from the civil defense tunnel excavation space effect,with deformation trends moving towards the excavation side,while the deformation values are all below the regulation-specified warning limits.

关 键 词：地铁隧道 人防隧道 小净距下穿 结构稳定性 

分 类 号：U455.1[建筑科学—桥梁与隧道工程]