| 摘要 |
PROBLEM TO BE SOLVED: To provide an arch-tunnel bottom slab capable of reducing weight to reduce cost. SOLUTION: When nuts 8 are screwed on a PC steel material 3 inserted into a through-hole 1c to introduce prestress, a force bending sidewalls 1b to the insides is added to the side walls of the bottom slab 1. A reinforcing member 4 fixed to a stage section 1d bears the axial compressive force to prevent the bending of the bottom slab 1. Under a state with the completion of an arch tunnel fixing precast wall slabs 10 on the sidewalls 1b of the bottom slab 1, the precast wall slabs 10 and load such as soil or the like backfilled on them act on the sidewalls 1b so as to force them to open to the outside, but the reinforcing member 4 prevents the sidewalls 1b from being deformed outwardly. By the constitution, since strength is reinforced by the reinforcing member 4, weight reduction can be made readily as well as reduction of cost.
|
