| 摘要 |
PROBLEM TO BE SOLVED: To solve a problem of breakage caused by joint dislocation due to frost heaving, or vibration from the ground although leakage shutoff work in a manhole is executed by inserting a urethane-based sealing material in a joint of the manhole, or the like. SOLUTION: The manhole 2 is constructed by piling up the suitable number of intermediate cylindrical frames 2B of cylinder shape, an upper cylindrical frame 2C of inverted funnel shape and a cover 2D in this order on a lower cylindrical frame 2A of bottomed cylinder shape. The leakage shutoff implement is composed of a leakage shutoff implement body for the manhole formed of natural synthetic rubber to correspond to the inner peripheral surfaces of the upper cylindrical frame 2C, intermediate cylindrical frames 2B and lower cylindrical frame 2A of the manhole 2, and retaining rings for attaching it. COPYRIGHT: (C)2004,JPO
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