大跨小间距黄土隧道支护体系及施工方法研究  

Research on Support System and Construction Method for Large-section Small Spacing Tunnel in Loess

作　　者：谭忠盛[1] 孟德鑫[1] 石新栋 姬同庚 何历超[1] 

机构地区：[1]北京交通大学土木建筑工程学院,北京100044 [2]中交隧道工程局有限公司,北京100044 [3]河南省桃花裕黄河大桥投资有限公司,河南郑州450016

出　　处：《中国公路学报》2015年第11期82-89,97,共9页China Journal of Highway and Transport

基　　金：国家自然科学基金项目(51378053)

摘　　要：为了解决浅埋大跨小间距黄土隧道的设计、施工等技术难题,以桃花峪隧道工程为背景,开展了隧道合理支护体系及施工技术的研究。采用隧道现场对比试验方法,设置了小间距隧道相互影响分析试验段、不同隧道开挖方法对比试验段、型钢钢架支护体系与格栅钢架支护体系对比试验段、有系统锚杆与无系统锚杆对比试验段,在试验段内测试了隧道拱顶沉降、水平收敛、围岩压力、支护结构内力等,并对测试数据进行了综合对比分析。结果表明:在两隧道间距5m,且均采用CD法施工的条件下,后行隧道施工对先行隧道的影响较小;在喷射混凝土早期强度满足要求的条件下,型钢钢架与格栅钢架支护体系的控制变形及承载能力相当,均可适用于大跨小间距黄土隧道;在大跨小间距黄土隧道中系统锚杆作用效果不明显,可以取消,取消后可加快断面及早闭合,更有利于控制支护变形;直立中隔壁CD法更有利于控制拱顶沉降;在桃花峪隧道施工中,全隧成功采用格栅+喷射混凝土支护体系,并全部取消系统锚杆,施工采用直立中隔壁CD法,确保了施工安全,并节省了大量工程投资。To solve the design and construction technical problems of shallow buried large-section small spacing tunnel in loess,associating with Taohuayu Tunnel,the research on reasonable supporting system and construction technology of tunnel was performed.Adopting the method of field contrast test in tunnel,contrast test sections of interaction analysis between small spacing tunnels,different curve methods in tunnel,steel arch support system and grid arch support system,with/without systematic bolts were set and comprehensive comparison of the test results was made,which included monitoring vault subsidence,horizontal convergence,surrounding rock pressure,internal force of supporting structure etc.in test section.The results show that in the construction with adopting CD excavation method and the distance between two tunnel faces being 5 m,the construction of later tunnel has little effect on the former tunnel.When earlystrength of sprayed concrete meets the requirement,the controlling deformation capacities of the two kinds of supporting systems are similar,therefore,which all could be applied to large-section small spacing tunnel in loess.There is little improvement of supporting effect on the systematic bolts in large-section small spacing tunnel in loess,thus systematic bolts can be cancelled to quicken the enclosed time of the initial supporting section and control the supporting deformation.CD excavation method of the vertical partition wall would be helpful for controlling crown settlement.It succeeds to apply grid and sprayed concrete support system to the in-situ construction of Taohuayu Tunnel,in which systematic bolts are cancelled and CD excavation method of the vertical partition wall is applied,to make sure the safety of construction and reduce the amount of engineering investment.

关 键 词：隧道工程 大跨小间距黄土隧道 现场试验 格栅钢架 型钢钢架 系统锚杆 

分 类 号：U455.91[建筑科学—桥梁与隧道工程]