| 摘要 |
PROBLEM TO BE SOLVED: To provide a small size manhole device excellent in workability. SOLUTION: A lower frame 11 equipped with a clean-out 12 opened upward, an inlet port 13 for making sewage flow thereinto from the outside and an outlet port 14 for making sewage flow therefrom to the outside is molded from resin concrete. A synthetic resin-made riser 31 is connected to the clean-out 12 of the lower frame 11 in a water-tight state. A resin concrete-made upper frame 41 is connected upward of the riser 31 in a water-tight state. In comparison with the synthetic resin-made lower frame 11 and riser 31, the surrounding soil in which the lower frame 11, the riser 31 and the upper frame 41 are baried is not compacted. Since the riser 31 is molded from a synthetic resin, the height can be easily and finely adjusted by cutting off the riser 31. Accordingly, workability can be improved.
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