| 摘要 |
<p>PURPOSE: To prevent sand and gravel from settling in a space, by forming a vertical space through a cobble stone for installation of filter media, and providing a water passage extending in the crossing direction at right angles and disposing a netted bag containing the filter media in the space. CONSTITUTION: A netted bad (c) containing filter media (b) is attached in a bed protection block body (a). A continuously connected part 5 extending from a fan-shaped part to a circular part 3 is formed in the radial direction of the lower fan-shaped part. In this time, the filter media (b) contained in the netted bag (c) are arranged in the space for the media, vertically extending through the bed protection block body (a) to filter a river water stream and reduce suspended solids. In this case, when pumice or the like is used as filter media (b), the media float in the arranging space and prevent the sand and gravel sliding dot to the downstream from piling in the space.</p> |
