Research on the Construction Technology for Deep-buried Long Tunnel in High-pressure and Water-rich Stratum
QING San-hui, YANG Jia-song, HUANG Shi-hong(China Railway Erju Co. Ltd, Chengdu, Sichuan 610032, China)
Research purposes:Jinping Tunnel, the total length of 17.5 km, locates in fault, fracture and karst development area, with deep buried depth of 2 375 m and blind heading with long distance trackless transport of 9 800 m, and the time limit for construction of it is 50 months, so it is urgently necessary to do the researches on how to prevent the geological disaster of high-pressured water bursting and the other disasters caused by rock blasting for the purpose of guaranteeing the construction safety.Research results:Based on the hydrodynamic simulation test, much high-pressured ground water is plugged effectively by taking the measures of selective plugging, curtain grouting in advance, vertical grouting-plugging and grouting-plugging with gunny bags and string bags. Based on numerical simulation test with discrete element method, rock blasting disaster is prevented by talking the measures of relaxing stress in advance, controlling blast, and using expansion anchor bolt, mesh and steel arch rib and spraying the concrete with thin zeolite powder additive. Based on the aerodynamic simulation test, large powerful jet fan and jet gallery ventilation technology are developed, which settled the technical problem of the ventilation for the construction of blind heading with long distance trackless transport and created the world record of blind heading with trackless transport of 9 800 m. After doing the research on integrated geological forecast in advance and the technologies of shot-concrete in rock blast and water-rich section, fast construction and supervision of long tunnel, the geological forecast accuracy is increased to above 85% and construction efficiency is improved much. The successful construction of Jinping Tunnel brings out a set of comprehensive construction technology for deep-buried long tunnels in high-pressure and water-rich stratum and promotes the development of tunnel construction technology in China.
【CateGory Index】： U455.49