BASE ISOLATION AND WATER ISOLATION WORK METHOD AT JOINTING PORTION OF VERTICAL SHAFT AND BASE ISOLATION AND WATER ISOLATION CONSTRUCTION

摘要

PROBLEM TO BE SOLVED: To greatly decrease section force at jointing portion of a vertical shaft by giving a base isolation to a jointing portion between a shield tunnel and a vertical shaft at the lowest cost possible and by improving the water isolation at the pit mouth of the shield tunnel. ;SOLUTION: At the jointing portion between a vertical shaft 11 and a shield tunnel 12, an end portion at the inner side of a segment 16a of a pit mouth is projected out to the inner side of the structural body 11a of the vertical shaft, the segment 16a at the pit mouth and the structural body 11a of the vertical shaft are insulated by a rubber-shaped insulation layer 19, cast-in-place concrete 20 is placed at its outer peripheral portion and is jointed to the structural body 11a of the vertical shaft. Also, a vibration isolation material is injected to a gap between the segment 16 of the shield tunnel 12 and the ground improving portion 13 thereby forming a base isolation layer.;COPYRIGHT: (C)1999,JPO