連続帯工群を敷設した直線河道における交互砂州の挙動

抄録

Riverbed girdles are one of the consolidation works to prevent bed-degradation and local scour around foundation of revetment in middle and small river channels. This study deals with fluctuations of alternate bars through a series of riverbed girdles in a straight alluvial river. Although the plane shape of riverbed girdle is basically set straight across the channel, we test some kinds of upstream- or downstream-pointing V-shaped weirs for the purpose of maintaining the alternate bars under this channel condition. In order to estimate the functions of a series of riverbed girdles, we apply two-dimensional numerical model Nays2DH and verify the effects of maintaining alternate bars by the experimental study. In cases with series of upstream-pointing V-shaped type with interior angle 80 degree, it is shown that the alternate bars are maintained without becoming extinct.