LINING OF SHIELDING TUNNEL AND STEEL SEGMENT FOR SECONDARY LINING

PROBLEM TO BE SOLVED: To attain economical design by improving dynamic strength and water stop property to internal water pressure or the like, assembling property and workability. SOLUTION: Plural steel segments A for secondary lining are assembled in a ring shape on the internal space side of primary lining of a shielding tunnel by butting welding or the like. In the steel segments A for secondary lining, CT shape steel 2 on which bending is performed is similarly welded and joined in the tunnel circumferential direction to the bedrock side of a steel plate 1 on which bending is performed in a finish radius of a tunnel, and a stiffening material 3 is also welded and joined in the tunnel axial direction. Plural holes 5 are arranged in the stiffening material 3 to reduce weight. A rubber material 4 is arranged in a part contacting with primary lining on a flange outside surface of the CT shape steel 2, and a damage preventive effect and a cushion effect of primary lining are imparted. A synthetic resin foaming body is filled between a segment for primary lining and the steel segments A for secondary lining.