砂岩地层多线隧道并行施工风险防控及结构安全分析  

Risk Prevention-control and Structural Safety Analysis of Multi-line Tunnel Parallel Construction in Sandstone Strata

作　　者：马晓波[1] MA Xiaobo(China Railway First Survey and Design Institute Group Co.,Ltd.,710043,Xi’an,China)

机构地区：[1]中铁第一勘察设计院集团有限公司,西安710043

出　　处：《城市轨道交通研究》2024年第12期32-38,45,共8页Urban Mass Transit

基　　金：陕西省科学研究与发展计划项目(2016TKC-07)。

摘　　要：[目的]多线隧道并行施工过程中,后行隧道开挖会对既有隧道造成不利的扰动影响。相较于双线隧道,多线隧道并行施工导致的扰动问题更为复杂,因此需针对其风险防控策略及结构安全开展研究。[方法]以某轨道交通区间线路和停车场站暗挖隧道工程为例,对其进行风险识别、防控及安全分析。利用结构可靠度准则量化判定3线隧道并行施工时的强影响区域。介绍了针对强影响区域内的既有暗挖隧道风险防控方法,即洞内加固措施。建立三维精细化数值模型,分析隧道不同并行施工阶段对应的地面沉降和既有隧道受力变形情况,评估了结构安全状态和加固措施的可靠性。[结果及结论]净距较小的既有暗挖隧道在右线盾构开挖过程中表现出明显的位移和变形,后行盾构隧道造成的扰动影响随着其与先行隧道间距离的增加呈现出明显的降低趋势。采用横撑和拱棚的整体加固措施能够有效减缓由于后行盾构隧道施工扰动导致的既有结构额外变形和受力。[Objective]During the parallel construction of multi-line tunnels,the excavation of subsequent tunnels will adversely disturb existing tunnels.Compared to double-line tunnels,the disturbance caused by multi-line tunnel parallel construction is more complex,necessitating researches on risk prevention-control strategies and structural safety.[Method]Using a rail transit interval line and depot station underground excavation tunnel project as example,risk identification,prevention-control and safety analysis are conducted.The structural reliability criteria are used to quantify and determine highly affected areas during three-line tunnel parallel construction.The risk prevention-control measures for existing underground excavation tunnels in these highly affected areas,specifically in-tunnel reinforcement measures are introduced.A three-dimensional refined numerical model is established,the land subsidence and existing tunnel stressed deformation corresponding to different stages of tunnel parallel construction are analyzed,and the structural safety states and reliability of reinforced measures are evaluated.[Result&Conclusion]Existing underground excavation tunnels with small clearance exhibit significant displacement and deformation during the excavation of the right-line shield tunnel.The disturbance impact caused by the subsequent shield tunnel decreases significantly as the distance from the preceding tunnel increases.The overall reinforcement measures using cross braces and arch canopies can effectively mitigate the additional deformation and stress on existing structures caused by the disturbance of subsequent shield tunnel construction.

关 键 词：多线隧道 并行施工 风险防控 结构安全 

分 类 号：U231.3[交通运输工程—道路与铁道工程]