水布垭地下厂房1号施工支洞围岩稳定性分析  

Stability analysis of surrounding rock of no.1 underground powerhouse in shuibuya

作　　者：王宵亮 王孔伟 聂进[1] 滕明明 路永强 Wang Xiaoliang;Wang Kongwei;Nie Jin;Lu Yongqiang;Teng Mingming(Key laboratory of geological hazards in the three gorges reservoir area,ministry of education(three gorges university),443002)

机构地区：[1]三峡库区地质灾害教育部重点实验室(三峡大学),443002

出　　处：《灾害与防治工程》2020年第2期10-21,共12页Disaster and Control Engineering

基　　金：国家自然科学基金重点项目(No.51439003)资助。

摘　　要：在地下洞室的开挖过程中,围岩以块体的形式发生失稳破坏,首先发生破坏失稳的块体称为“关键块体”。本文以水布垭水电站地下厂房1号施工洞室为例,根据关键块体理论的基本原理,采用赤平投影法与矢量分析法识别可能的关键块体,采用Unwedge程序对关键块体稳定性进行评价,运用三维数值计算,对1号施工支洞的长期稳定性进行了评价,得出如下结论:1号施工支洞破坏形式表现为受局部裂隙组合控制的块体不稳定;确定了组合2、3、4、5构成的局部块体皆为可动块体;组合2,组合5所确定的块体处于不稳定状态;1号施工支洞受裂隙及其组合的影响明显,具有明显的时间效应。当隧道开挖后整个隧道的拱顶下沉和应力不大,三个关键断面的拱顶下沉值达到了2.10-2.33cm,且拱顶出现了约0.19-0.36MPa范围的拉应力,极有可能造成该部位的破坏。During the excavation of the underground cavern,the surrounding rockswere destabilized and destroyed in the form of blocks.The block that is the firstto undergo instability is called the"critical block".This article takes the No.1 construction cavern of Shuibuya Hydropower Station underground powerhouse as anexample and uses the orthographic projection method and the vector analysis method to identify possible critical blocks.The Unwedge program was used to evaluate thestability of critical blocks.Using three-dimensional numerical calculations,thelong-term stability of the No.1 construction branch tunnel was evaluated,and thefollowing conclusions were reached:①The failure form of construction branchtunnel No.1 manifested as block instability controlled by local crack combination;②It is determined that the local blocks composed of combinations 2,3,4,and 5are all movable blocks;③The blocks identified by combination 2 and 5 are in anunstable state;④The construction tunnel No.1 is obviously affected by cracksand their combinations,and has obvious time effects.When the tunnel is excavated,the vault of the entire tunnel doesn't sink much and has little stress.Thesubsidence of the vaults at the three key sections reached 2.10-2.33cm and a tensilestress in the range of about 0.19-0.36 MPa appears in the vault,which is likelyto cause damage to this part.

关 键 词：块体理论 水布垭水电站 地下洞室群 稳定性分析 

分 类 号：U45[建筑科学—桥梁与隧道工程]