| 摘要 |
<P>PROBLEM TO BE SOLVED: To reduce life cycle costs while prolonging an overall lifetime by suppressing parts to be reconstructed to an irreducibly minimum by performing partial reconstruction, even in a free gradient existent culvert side ditch comprising precast concrete of a gate-shaped structure and partial covering, by removing only a fixed upper slab of an upper part while burying the side ditch, by maintaining a lower part of a main body, and while also keeping a bottom face gradient. <P>SOLUTION: An upper slab part of a gate-shaped free gradient existent culvert side ditch is removed. At the same time, an upper slab block 3 of precast concrete is erected and loaded in a fixed upper slab part removed position between walls of a main body to be maintained, which are obtained by slitting upper parts of both the side walls at a right angle, while accommodating and fixing expansion steel beams 11 on both side faces within the right-angle slits of the upper parts of both the side walls in the main body to be maintained. <P>COPYRIGHT: (C)2013,JPO&INPIT |
