STABILIZING METHOD FOR GROUND IN TUNNEL EXCAVATION AND INJECTION PIPE USED THEREIN

摘要

PURPOSE:To reduce an expense of construction while stabilizing the uniform ground without generating blinding by storing to a water level not less than the groundwater level a grain-size adjusting clay suspension naturally infiltrated into the ground from an injection pipe provided in the face sandy ground. CONSTITUTION:A fixed water level tank 26 is provided in a water level not less than the groundwater level W, storing a classification processed grain-size adjusting clay suspension A. Next, an injection pipe 15 is buried toward a tunnel advancing direction and press inserted to a predetermined length while injecting from a water injecting pipe 17 water washing away grits. Next the liquid A is injected by a head pressure through an injection line 30 into the ground G from an injection pipe main unit 16. In this way, a sufficient amount of clay grains is infiltrated in an unsolidified sandy layer total unit without generating blinding and replaced with water, and an expense of execution can be reduced by a simplified equipment while increasing strength and water stop quality of the ground G, further even excavation can be smoothly executed because the necessity for providing a tunnel equipment is eliminated.