Peel off protective structure of the tunnel lining

摘要

PROBLEM TO BE SOLVED: To provide a protecting structure for a lining inner face of an existing tunnel capable of being quickly constructed. SOLUTION: In this protecting structure C covering the inner face of the existing tunnel by mounting face members 2 on the arch timbers A, the arch timbers A are respectively formed by engaging plural circular arc-shaped arch forming members 1 provided with engagement joints on their circumferential end parts in series, a side face of each arch forming member is provided with a groove 15 or a stepped part for mounting the face member 2, lower ends of the arch timbers A are fixed to the existing tunnel 32 by means of a fixing means. The face members 2 set between the arch timbers A are respectively formed of thin panels having a dimension mountable in the groove 15 or the stepped part of the arch forming members 1. At least the back faces of the arch timbers are closely kept into contact with the existing tunnel wall face 6a approximately over the whole circumferential face through a closely contact means.