| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a tunnel cut-off structure capable of smoothing a fastening site between waterproof sheets neighboring each other in the axial direction of a tunnel while eliminating the occurrence of slack therein, resulting in highly durable waterproof effects.SOLUTION: In the tunnel cut-off structure, approximately planar waterproof sheets 51 provided inside a tunnel pit face 25 while being tied to one another are fixed away from the inner face of a spray concrete 3 provided inside the tunnel pit face 25, and a first waterproof sheet 51p, a second waterproof sheet 51q and a third waterproof sheet 51r, each formed as the waterproof sheet 51, are provided while being tied sequentially to one another in the boring direction of the tunnel. In the state that tensile stress occurs in the second waterproof sheet 51q in the axial direction of the tunnel, a rear end 51a and a front end 51b of the second waterproof sheet 51q in the boring direction of the tunnel are fastened to a front end 51b of the first waterproof sheet 51p on the rear side and to a rear end 51a of the third waterproof sheet 51r on the front side while overlapping therewith, respectively.</p> |
