| 摘要 |
<P>PROBLEM TO BE SOLVED: To allow groundwater to be smoothly drained into a manhole when excess pore water pressure or groundwater pressure increases and may cause increase in buoyancy against the manhole. <P>SOLUTION: A floating prevention structure of a manhole is configured such that groundwater is drained from a wall face in order to mitigate increase in excess pore water pressure or groundwater pressure which may cause increase in buoyancy and the manhole is prevented from floating, including during an earthquake. The floating prevention structure has water collecting regions 3 in communication with through holes 2 formed in a wall face of the manhole 1 and formed in the natural ground. The water collecting regions 3 are constituted of a water collecting material which is replaced with soil of the natural ground C. The water collecting material of the water collecting regions 3 can be washed by supplying washing water to the water collecting regions 3 via the through holes 2. <P>COPYRIGHT: (C)2013,JPO&INPIT |
