隧道双侧近接既有偏压浅埋隧道施工影响研究  

Research on the Influence of the Construction of Tunnels Close to Existing Bias Shallow Buried Tunnel on Both Sides

作　　者：王志杰[1] 蔡李斌 李振[1] 张曾照 王宁 邱志洪 蒋新政 WANG Zhijie;CAI Libin;LI Zhen;ZHANG Zengzhao;WANG Ning;QIU Zhihong;JIANG Xinzheng(Key Laboratory of Transportation Tunnel Engineering of Ministry of Education,Southwest Jiaotong University,Chengdu,Sichuan 610031,China;China Railway Design Corporation,Tianjin 300142,China)

机构地区：[1]西南交通大学交通隧道工程教育部重点实验室,成都610031 [2]中国铁路设计集团有限公司,天津300142

出　　处：《铁道工程学报》2021年第3期53-58,106,共7页Journal of Railway Engineering Society

基　　金：中国铁路总公司科技研究开发计划课题(2017G007-E);中央高校基本科研业务专项资金资助项目(SWJTU11ZT33);教育部科研创新团队发展计划资助项目(IRT0955)。

摘　　要：研究目的:浦梅铁路新建隧道双侧近接既有偏压浅埋隧道工程的不良地质问题突出,近接形式独特,施工过程中缺乏有效的理论和实践方法指导。本文以该工程为依托进行拓展研究,利用数值模拟和理论分析方法,对不同偏压角度和净距条件下的近接施工影响规律进行系统研究。研究结论:(1)偏压角度增加会提高近接施工的扰动性,主要表现为既有隧道的拱腰及以上部位变形增大、边墙以上部位塑性区范围扩大,结构受力增加、对边坡稳定性干扰加重;(2)既有隧道拱顶由于卸荷回弹会发生抬升变形,且随着S_(1)增大呈现先增大后减小的变化规律,在S_(1)=0.5D取得最大值;两侧拱腰由于坡体失稳会发生浅埋向变形,且随着S_(1)增大呈现先减小后增大的变化规律,在S_(1)=0.5D取得最小值;(3)既有隧道衬砌结构在墙脚部位发生显著应力增长,在实际受力监测过程中,对于边墙以上部位应重点关注深埋侧,边墙以下部位应重点关注净距较小侧;(4)当浅埋侧隧道与既有隧道净距较大时,应做好边坡防护;(5)本研究结果对于隧道双侧近接既有偏压浅埋隧道施工影响及其相关研究具有一定参考借鉴作用。Research purposes:The bad geological problems are prominent in the construction of the new tunnels of Pucheng-Meizhou railway,which is connected to existing biased shallow buried tunnel on both sides.There is a lack of effective theory and practice method guidance in the construction process.Based on this project,this paper makes a systematic study on the influence law of proximity construction under different bias angles and net distances by means of numerical simulation and theoretical analysis.Research conclusions:(1)The increase of the bias angle will improve the disturbance of the adjacent construction,which is mainly manifested as the increase of the deformation of the arch waist and above of the existing tunnel,the expansion of the plastic zone above the sidewall,the increase of the structural stress and the increase of the disturbance to the slope stability.(2)The existing tunnel vault will be uplifted and deformed due to unloading rebound,and with the increase of S_(1),it first increases and then decreases.The maximum value is obtained at S_(1)=0.5D.Since the slope body is unstable,the arch waist on both sides will have shallow buried deformation,and with the increase of S_(1),it first decreases and then increases.The minimum value is obtained at S_(1)=0.5D.(3)The lining structure of existing tunnel experiences significant stress increase at the wall foot.In the actual stress monitoring process,the deep buried side should be focused on the part above the sidewall and the side below the sidewall with a small net distance.(4)When the net distance between shallow buried side tunnel and existing tunnel is large,slope protection should be done well.(5)The research results can be used as a reference for the construction influence of the existing bias pressure shallow buried tunnel on both sides of the tunnel and the related research.

关 键 词：铁路隧道 双侧近接 偏压角度 净距 数值模拟 

分 类 号：U25[交通运输工程—道路与铁道工程]