APPARATUS FOR SPREADING WIDTH OF EXISTING TUNNEL

摘要

PROBLEM TO BE SOLVED: To provide an apparatus for spreading the width of an existing tunnel, which enables safe width-spreading work in a short construction period while keeping the tunnel in service conditions. SOLUTION: The apparatus is formed of a protector 2 which has its inner space penetrated in a tunnel axial direction, and a movable work frame 3 which is shorter in length in the tunnel axial direction than the protector and arranged astride the protector. The work frame is movable in the tunnel axial direction independently from the protector. Alternatively, the protector may be movable in the tunnel axial direction independently from the work frame. COPYRIGHT: (C)2003,JPO