ADVANCE/ARRIVAL DOOR FOR VERTICAL PIT FOR TUNNEL EXCAVATION

摘要

PURPOSE:To simplify the advance/arrival work of a shield excavating machine, shorten the construction period, and reduce the construction cost, by obviating the need of the improvement of ground and the freeze-processing work. CONSTITUTION:A door body 13 for closing the opened port part 12 of a caisson 11 is formed by combining long divided bodies 15 in parallel, and the cut part 15C of the divided body 15 is formed to a plate shape, and a sandproof wall 14 which can be excavated by the front surface part shield excavator of the door body 13 is laid, and the cut part 15c is cut on each divided body 15 when the door body 13 is withdrawn, and withdrawal-removed. The inflow of the soil and sand is prevented by the sandproof wall 14 in the withdrawal, and the sandproof wall 14 is breakage-excavated by advancing the shield excavating machine C, and advanced to arrival.