紫坪埔隧道小净距段现场监测试验研究  

EXPERIMENTAL STUDY OF SITE MONITORING OF ZIPINGPU TUNNEL WITH SMALL CLEAR SPACING

作　　者：姚勇[1,2] 何川[2] 张玲玲[1] 

机构地区：[1]西南科技大学土木工程与建筑学院,四川绵阳621010 [2]西南交通大学地下工程系,四川成都610031

出　　处：《岩石力学与工程学报》2010年第A01期3295-3300,共6页Chinese Journal of Rock Mechanics and Engineering

基　　金：西部交通建设科技项目(2003-318-780-12)

摘　　要：为节约工程造价,紫坪铺隧道汶川端设计为渐变小净距隧道与整幅修建的泯江大桥相接。该端隧道洞口段左、右线间距较小,围岩较差。为保证隧道的安全施工和积累经验,对紫坪埔隧道小净距段进行衬砌内力、围岩压力、位移及地表沉降等项目的监测工作。现场监测结果表明:(1)后行洞开挖对中岩墙及先行洞的围岩及结构均产生一定的影响,影响程度视围岩级别不同而不同;(2)采用上下台阶法施工时,上下台阶交界部位是应力集中和初期支护薄弱之处,施工中应加强对上下台阶交界处的监控量测;(3)中岩墙是小净距隧道的薄弱环节,为保证施工过程中的安全,应加强对中岩墙应力、位移的监控量测。For the purpose of saving construction cost, Wenchuan portal section of Zipingpu tunnel is so designed that twin tunnels in close proximity connected with Minjiang River bridge. On this portal section the spacing between right and left lines is small and the wall rock between them is weak. For the safety of tunnel construction, some monitoring tasks have been performed in Zipingpu tunnel, including the ground settlement, surrounding rocks pressure and internal force in lining, etc. Based on the measured data, it is shown that： （1） the influence of the later excavated tunnel on antecedence tunnel and the wall rock is existent in the construction of twin-bored tunnels, but the degree of influence is different. The surrounding rock is weaker, the extent of the influence is bigger. （2） The stress of the juncture section of the neighbor steps is relatively centralized, and the initial support is the most weak. The site monitoring is advised to adopted in the construction. （3） Because the wall rock is the most weak link in the construction of the small-distance tunnel, it is advised to take measures（such as the rational method of construction and site monitoring, etc.） to ensure the safety in the construction of Zipingpu tunnel.

关 键 词：隧道工程 小净距 现场监测 

分 类 号：U45[建筑科学—桥梁与隧道工程]