抄録
Longitudinal bed profiles and sedimentary bed-forms, one experiment without any groin and five with impermeable submersible groins in series experiments, were investigated in a 27.5m long straight channel in different arrangements of groins. Spectrum analysis of longitudinal profiles near and even very far from groin head showed large amplitude spectral peaks in the region of higher wave numbers. This indicated the groin bed's more irregular sand waves and non-equilibrium sediment transport than no groin bed having same the hydraulic conditions. The bed-form height and bed-form length followed a separate distribution function. The former fitted Rayleigh distribution well and the latter had Normal distribution. The van Rijn empirical formulae for bed-form height and bed-form steepness were modified, and bed-form height and length of groin bed might be estimated from the modified equations.
