Set-up/down plural-span weir assembly made of flexible sheets

摘要

A set-up/down plural-span weir assembly is made of flexible sheets and comprises a plurality of single-span weirs coupled to each other through pillars across the stream of a river. A pressure medium is introduced into the bags of the single-span weirs to inflate them to set up the single-span weirs and also discharged therefrom to deflate them to set down the single-span weirs. The upstream water of the weir assembly is directly introduced from an upstream water level detection pipe into a bucket or float container of at least one of the single-span weirs, and is indirectly introduced from the upstream water level detection pipe into the bucket or float container of at least another one of the single-span weirs through the bucket or float container of the former one of the single-span weirs or through that of still another one of the single-span weirs.