Journal of the Japan Society of Erosion Control Engineering, Vol.58,No.4,2005

Experiments on sediment trap reliability of hybrid buttress dams with lateral beams

Toru NAKAMURA Yuji HASEGAWA Akira ODA

Abstract

Since the slit sabo dams of clog type have been developed mainly using steel slits of vertical or lattice type, the effectiveness of the slit sabo dams using steel pipes installed in the lateral direction (lateral beams) for catching sediment in debris flow has not been examined much. Therefore, we experimentally examined how effectively a hybrid buttress type sabo dam using both vertical pillars (vertical slit) and lateral beams can catch mass]transport of sediment in debris flow, and further, how effectively another hybrid buttress sabo dam where subsidiary vertical materials are installed between the vertical slits can catch sparse]transport of sediment in traction.
The results are summarized as follows: if the lateral beams of the hybrid buttress dam are installed at intervals of 1.0~d95, the same effect on catching sediment can be obtained as in the case where the intervals of vertical pillars are set to 1.5~d95. Moreover, it proves that, aside from the strength of the materials, even subsidiary vertical materials which are as slender as wire can catch sediment effectively if their installation intervals are narrow. This suggests that if it is necessary to install the vertical materials at narrow intervals, the use of a slender material like wire can be effective in securing the opening rate of the sabo dam.installations.

Key words:hybrid buttress sabo dam, lateral beams, subsidiary vertical materials, debris flow, traction
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