EXTENSION METHOD OF EXISTING TUNNEL MAKING USE OF MOBILE WORKING PLATFORM

摘要

PROBLEM TO BE SOLVED: To provide an extension method of the existing tunnel making use of a mobile working platform capable of economically making widening in the case a total extension length is long or even in the case a section is small. SOLUTION: The extension method includes an upper half widening section 20 and a lower half widening section 22, and a widening tunnel 12 including the whole section of the existing tunnel 10 inside thereof is constructed. When the widening tunnel 12 is constructed, a simple protector 24 having an inverted recess section for ensuring the traffic of a vehicle is installed at the inside of a lining layer 14 of the existing tunnel 10, and the portal mobile working platform 26 capable of coating the outer circumference of the protector 24 is installed along the direction of the axis of the existing tunnel 10 in a movable manner. The excavation of the upper half widening section 20 and the fracture removal of the ceiling section 16 of the lining layer 14 are carried out by the excavator 36 mounted on the mobile working platform 26. The excavation of the lower half widening section 22 and the fracture removal of side walls 18 of the lining layer 14 are carried out by excavators 27 through work on the roadbeds on the sides of the mobile working platform 26. COPYRIGHT: (C)2003,JPO