How to build a shut-off valve pit for gas conduit

摘要

PROBLEM TO BE SOLVED: To provide a construction method of a gas conduit block valve pit which can make an operation space in a road width direction small, and can paste a waterproof sheet on an external peripheral face of the pit.SOLUTION: A construction method of a gas conduit block valve pit comprises: a step for installing steel piles at both sides in a direction along a gas conduit 1, and excavating a trench 3 for a pit by arranging a waling material at an upper end; a step for forming a bottom part at a bottom of the excavated trench; a step for forming a wall face at the inside of the steel pile; a first waterproof sheet pasting step for pasting waterproof sheets on the bottom part and the wall face; a step for installing a bottomed frame-shaped reinforced cage which holds piping connected to an existing gas conduit; a concrete-form installing/concrete placing step for installing concrete forms at the inside of the installed reinforced cage and on a gas conduit orthogonal face at the outside of the reinforced cage, and placing concrete to the reinforced cage; a removing step for removing the concrete-form; and a second waterproof sheet pasting step for pasting the waterproof sheets on the gas conduit orthogonal face of an outer peripheral wall of the pit.