| 摘要 |
PROBLEM TO BE SOLVED: To provide a manhole requiring an inclination angle as an essential requirement, but not requiring a top face width as a requirement, and in particular, not contrived in a manhole lid. SOLUTION: The manhole has the manhole lid filled with asphalt, and the top face width of the manhole lid and the top face width of a manhole receiving frame are made to be smaller than 10 mm. COPYRIGHT: (C)2011,JPO&INPIT
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