母线洞开挖时序对围岩位移的影响效应  

EFFECTS OF EXCAVATION SUBSEQUENCE OF BUSBARS TUNNEL ON DISPLACEMENT OF SURROUNDING ROCK MASS

作　　者：黄秋香[1] 邓建辉[2,3] 苏鹏云[4] 

机构地区：[1]成都理工大学地质灾害防治与地质环境保护国家重点实验室,四川成都610059 [2]四川大学水力学与山区河流开发保护国家重点实验室,四川成都610065 [3]四川大学水利水电学院,四川成都610065 [4]中国水电顾问集团成都勘测设计研究院,四川成都610072

出　　处：《岩石力学与工程学报》2013年第S2期3658-3665,共8页Chinese Journal of Rock Mechanics and Engineering

基　　金：成都理工大学地质灾害防治与地质环境保护国家重点实验室自主课题资助项目(SKLGP2011Z011)

摘　　要：以瀑布沟水电站地下厂房和溪洛渡水电站地下厂房为背景,以主厂房为研究对象,基于施工期围岩位移监测资料,借助数值模拟,分析母线洞采取不同开挖时序对围岩位移的影响。首先,借助监测成果,分工程部位(顶拱、岩锚梁、上游边墙、下游边墙)对比分析母线洞开挖采取先墙后洞和先洞后墙2种施工时序下围岩位移情况;然后借助数值计算,对Ⅱ, Ⅲ类围岩在高、中、低3种不同地应力条件下母线洞开挖分别采用先洞后墙和先墙后洞2种开挖过程进行模拟。综合分析现场监测成果及数值模拟结果,得出的结论为:母线洞施工时序对围岩位移的影响,主要体现在岩锚梁层及以上部位,其中以下游岩锚梁部位影响最大;从控制围岩位移的角度讲,当低地应力时,施工时序不同造成的影响差异不大,在中、高等地应力状态下适合采用先洞后墙的施工时序。作为与地下厂房相贯的洞群,施工时机的合理性具有工期控制及围岩稳定双重意义,不同地质条件下母线洞开挖时序的影响效应值得深入探讨。Generally,there are two different schemes about the excavation subsequence of main powerhouse and tunnels that intersect with it at intersecting section. One is that the part of main powerhouse is excavated first,and then the part of tunnel is excavated from side wall of main powerhouse,which is called first side wall then tunnel. While the other is on the contrary,that means the tunnel is excavated first then the part of main powerhouse is excavated from the tunnel,which is called first tunnel then side wall. With Pubugou hydropower station underground powerhouse and the Xiluodu hydropower station underground powerhouse as background,taking main powerhouse as object of study,the effect of the bus tunnel construction sequence use the scheme of first tunnel then side wall or first side wall then tunnel on surrounding rock displacement is analyzed based on monitoring data and by means of numerical simulation. Firstly,with the help of monitoring results,the displacement of surrounding rock mass of top arch,rock anchor beam,upstream side wall,as well as downstream side wall were compared part by part;then by using numerical calculation,in which main factors considered were ground stress and rock types,rock type of II or III,ground stress in high,medium,as well as low level,busbars tunnel was excavated by using the scheme of first tunnel then side wall or first side wall then tunnel,that means 12 different conditions were simulated. The research results from comprehensive analysis of monitoring results and numerical simulation results show that,the effect of bus tunnel construction sequence on surrounding rock displacement is mainly concentrated in the place of anchor beam layer and above parts,especially at layer of rock anchor beam in the downstream. From point of control surrounding rock displacement,in condition of low stress, the influence of excavation subsequence is not obvious,while in the condition of medium and high stress the opinion that tunnels are excavated first is preference. As cavern that inters

关 键 词：水利工程 地下厂房 围岩位移 安全监测 母线洞开挖时序 

分 类 号：TV223.1[水利工程—水工结构工程]