既有隧道扩挖改造的施工控制及数值模拟研究  

Research on the Construction Control and Numerical Simulation of the Existing Civil Air- defence Tunnel Reconstruction

作　　者：刘明辉[1] 殷爱国 郭伟 

机构地区：[1]华北水利水电大学,郑州450045 [2]中铁七局集团有限公司,郑州450016

出　　处：《铁道工程学报》2014年第11期98-103,共6页Journal of Railway Engineering Society

基　　金：国家自然科学基金(51308214)

摘　　要：研究目的:由于既有人防隧道的扩挖改造施工在国内鲜有实例,本文综合应用监控量测技术和有限元分析理论,模拟研究结构单双侧扩挖动态掘进各阶段的位移、变形及受力特征,并将数值模拟结果与实测结果进行了对比分析,通过完善施工方案并加强施工控制,保证施工安全。研究结论:(1)单、双侧扩挖造成的地表最大沉降值、围岩结构应力等主要指标均满足规范和设计要求,表明制定的施工方案合理;(2)随着整个隧洞的扩挖,围岩结构呈拉应力减小、压应力增加的趋势,其最大拉应力在施作初期支护和临时支撑时剧减,其最大压应力在顶部结构凿除时剧增;(3)单侧扩挖每次凿除2 m既有结构,地表的最大沉降值达到15.10 mm,而双侧扩挖每次凿除1 m既有结构,地表的最大沉降值达到23.67 mm,此值非常接近设计警戒值(24 mm),施工的时候应该严格控制;(4)提出了采用临时竖撑预支加固、先侧墙后仰拱、径向注浆、管棚支护和跳槽扩挖等施工方法和措施,使既有结构内力变化在可控范围内,有效地控制了拱顶沉降、仰拱上浮和地层位移,保障了结构和施工安全;(5)通过总结既有人防隧道扩挖改造施工过程中围岩、地表、衬砌结构等的变形规律,为同类工程的设计和施工提供借鉴。Research purposes： The existing civil air defense tunnel reconstruction gets few examples in China. This paper relies on monitoring measurement technology and the theory of finite element analysis, studies the displacement, deformation, and stress characteristics on different stages of dynamic tunneling during the single and bilateral excavation. We improved construction plan, strengthened the construction process control, and compared the numerical simulation results with site measures to ensure the safety of tunnel reconstruction. Research conclusions： （ 1 ） The main parameters such as the maximum ground settlement caused by unilateral and bilateral excavation and the stress of surrounding rock meet the code and design requirements. This shows that the construction scheme is reasonable. （2） The rock structure experiences a trend of decreasing tensile stress and increasing compressive stress with the excavation. The maximum tensile stress of the rock structure drops dramatically as the initial support and temporary support. The maximum compressive stress increases dramatically when the top structure is excavated. （3） A two - meter single side excavation of the existing structure is followed by a ground surface sedimentation of 15. 10 mm while a one -meter bilateral excavation expects a ground surface sedimentation of 23.67 mm, which is very close to the designed warning value （24 mm） and shall be strictly controlled during the construction. （4） This paper presents the construction methods and measures such as temporary vertical advance reinforcement, side wall and invert, radial grouting, supported by pipe shed, excavation and so on, which can make the internal force change under control, control the displacement of vault, the inverted arch and surface effectively, and ensure the safe of structure and construction. （5） This paper summarizes the deformation rules of surrounding rock, surface, liner structure and so on, which can provide references for the design and construction of sim

关 键 词：人防隧道 扩挖改造 施工控制 数值模拟 跳槽施工 

分 类 号：TU231.3[建筑科学—建筑设计及理论]