摘要
广西驮英灌区客兰东干渠10座隧洞建成超过40年,部分隧洞因年久失修出现塌陷,为此开展隧道整体扩建施工。水利特小断面隧洞在改扩建洞挖时,同一掌子面爆破开挖中存在原有旧洞围岩被扰动、围岩破碎、爆破扩挖后掌子面掉块严重的问题,这导致设计开挖轮廓线与爆破后实际成形洞面轮廓线之间出现有较大空腔。为此,提出超前加固并对不同围岩掌子面分段爆破开挖的施工技术,确保了开挖与初期支护时掌子面施工安全,并降低施工成本与工程造价。
Based on the fact that 10 tunnels of East Kelan trunk canal in Tuoying Irrigation Area of Guangxi have been constructed for more than 40 years and some tunnels have collapsed after years of disrepair,overall expansion construction is conducted.During the reconstruction and expansion of small section hydraulic tunnel and the blasting excavation of the same face,the surrounding rock of the old tunnel is disturbed,the surrounding rock is broken,and the block is seriously dropped after the blasting excavation.As a result,there is a large cavity between the designed excavation contour line and the actual formed tunnel surface contour line after blasting.In order to solve this problem,the construction technology of advance reinforcement and sectional blasting excavation for different surrounding rock faces is proposed,ensuring the construction safety of the working face during excavation and initial supportand reducing the construction cost and engineering cost.
作者
晁增福
CHAO Zengfu(China Railway Guizhou Engineering Limited Company,Guiyang 550000)
出处
《现代隧道技术》
EI
CSCD
北大核心
2020年第S01期1042-1046,共5页
Modern Tunnelling Technology
关键词
特小断面
改扩建隧洞
分段爆破
掉块
施工安全
Extra-small section
Reconstruction and expansion of tunnel
Sectional blasting
Block drop
Construction safety
