| 摘要 |
PROBLEM TO BE SOLVED: To provide a drain side ditch which prevents permeability of a road surface from being deteriorated.SOLUTION: A drain side ditch is installed in a water-permeably paved road surface, and is constructed as a covered conduit in which a drain hole 2 extending in the longitudinal direction is formed in the cross-sectional central part of a thick concrete body part 1. In a lid part above the drain hole 2 in the body part 1, a surface long groove 6 introducing surface rainwater on a water permeable layer upper surface of the road surface, surface vertical holes 7 passing from the surface long groove 6 to the drain hole 2, an internal long groove 8 for introducing internal rainwater immersing into an impermeable layer P2 of the road surface, and internal vertical holes 7 passing from the internal long groove 8 to the drain hole 2 are formed. Shallow pan-shaped water conducting recesses 10 are formed in a connection part of the internal vertical holes 7 to the internal rainwater long groove, and filters 20 covering respectively the water conducting recesses 10 are provided. A space is left because the water conducting recess 10 is formed under the underside of the filter 20. Thus, a passage space for rainwater is secured and water is not accumulated on the water-permeably paved road surface even in the case of heavy rainfall. |
