摘要
Abstract
The excavation method of the shallow buried tunnel section of North Trunk Canal in Letan Reservoir Irri-gation Zone was changed from TBM to drilling and blasting method,so it was necessary to correspondingly modify and optimize the support lining design scheme for the shallow buried tunnel crossing karst clear spring area.For the shallow buried tunnel with the roof accommodated in surrounding rock of Ⅳ class,full section secondary lining was adopted only for the tunnel section with karst clear spring developed,permanent and temporary combined support technical scheme consisting of steel arch frame and bolt shotcrete support was adopted for the rest tunnel sections.For the underground river and spring in karst developed area,water diversion combined with leakage stoppage was carried out to ensure the structural safety of tunnel,and avoid the major risk resulting from excessive grouting seal-ing thickness blocking karst channels and waterways within the shallow buried tunnel roof range.关键词
浅埋隧洞/岩溶清泉区/支护衬砌方案/优化设计/桂中治旱Key words
shallow buried tunnel/karst clear spring area/support lining scheme/optimize design/Middle Guangxi drought control分类
建筑与水利
