CROSS SECTION WIDENING METHOD FOR EXISTING TUNNEL AND CROSS SECTION WIDENING DEVICE

摘要

PROBLEM TO BE SOLVED: To provide an existing tunnel cross section widening method and a cross section widening device for safely and easily carrying out widening of a cross sectional width of an existing tunnel as hot-line construction, by improving a blasting method, a protector, and a protection structure in order to properly comply with either of a machine excavation method and an excavation method by blasting.;SOLUTION: By means of this existing tunnel cross section widening method and the cross section widening device, the protector 2 is formed into a shape copying an inside hollow cross section 12 of the existing tunnel 10 and allowing passage of a passing body 6, and a protection barrier 5 is arranged in the rear end part of the protector 2. The front end part of the protector 2 is inserted into the inner hollow cross section 12 of the existing tunnel 10 to be arranged, and then, the cross section of the existing tunnel is widened by properly moving an excavating carriage 3 and a finishing carriage 4 to the outside/inside of the protective barrier 5.;COPYRIGHT: (C)2003,JPO