EXISTING PIPE RENEWAL METHOD

摘要

PROBLEM TO BE SOLVED: To shorten construction time, and to reduce construction cost.SOLUTION: A departure shaft H1 and an arrival shaft H2 are constructed at positions separated each other by a renewal length L of an existing pipeline, and existing pipes in its both shafts are cut and removed. A ring-shaped boring machine 10 having an excavation cutting tool 13 in a front part, is fitted to one end part of a renewal existing pipe in the departure shaft, and the boring machine is moved toward the arrival shaft while rotating its cutting tool, and excavates the ground G around the outer periphery of the existing pipeline. At the same time, muddy water (w) is sent into and sent back from an excavation part, and excavation sediment is sent out to the departure shaft. Since its excavation is executed by the cutting tool, efficiency is high, and since the excavation sediment is sent out by the muddy water, its efficiency is also excellent. When the boring machine reaches the arrival shaft, one end of a new pipe is connected to the rear end of a thrust transmission pipe 15 and a protective pipe 16 of the boring machine and one end of the existing pipe, and the existing pipe and the boring machine are sent out to the arrival shaft by successively pressing-in/propelling while connecting the new pipe, and the existing pipeline is renewed to be a new pipeline. The new pipes renewed in the departure shaft and the arrival shaft and an unrenewed existing pipe are connected, and the departure shaft and the arrival shaft are back-filled.