SETTING WORK OF WATER-COLLECTING TUBE FOR DRAINING GROUNDWATER UNDER GROUND OF TUNNEL WALL

摘要

PURPOSE: To prevent the runoff of sand and soil when draining groundwater during the setting period of water-collecting tubes. ;CONSTITUTION: A casing 3 whose tip is closed by a cap 5 is driven through the outer wall of tunnel into the ground, and a water-collecting tube 4 of an outside slightly diameter smaller than the inside diameter of the casing 3 is inserted through a soil runoff-preventing ring 6 into the casing 3. The tube 4 is driven to the advancing direction, the cap 5 is removed by pushing from the tip of the casing 3, and the casing 3 is then penetrated into the tunnel to leave the tube 4 with the cap 5 under the ground while preventing the runoff of soil by means of the ring 6. The water-collecting tube 4 can thus be effectively set under the ground.;COPYRIGHT: (C)1993,JPO&Japio