SEGMENT LINING WATER-PROOF SHEET RECEIVING FRAME FOR TUNNEL BORING MACHINE

摘要

PROBLEM TO BE SOLVED: To surely and smoothly weld the lapping section at the end of a new water- proof sheet which is used to line a segment of a tunnel in the tail plate of a tunnel boring machine to the corresponding lapping section of an already laid water-proof sheet in one body by means of a welding device at the time of laying the new sheet in a cylindrical shape. SOLUTION: After a heat insulating layer 4A is fitted to the inner peripheral surface of a cylindrical steel-made receiving frame 4 provided along the inner peripheral surface of the tail plate 2, a newly laid cylindrical water-proof sheet 5A is formed by lining the segment with the new belt-like water-proof sheet 5 so that the rear end section of the sheet 5 may lap on the front end section of the already laid water- proof sheet 5B while the sheet 5 is brought into contact with the inner peripheral surface of the frame 4. Then the lapping sections of the sheets 5A and 5B are integrally welded to each other by means of the electrically heated trowel 7A of the welding device 7. At the time of welding the lapping sections to each other, the occurrence of defective welds is eliminated by efficiently and entirely heat-welding the lapping sections to each other so as to prevent the infiltration of groundwater by preventing the heat from the trowel 7A from escaping to the frame 4 side by means of the heat insulating layer 4A.