Abstract: In order to investigate the homogeneous bank fall of reservoir and the changing features of the phreatic line during uniform rising water level, three homogeneous bank models with different structures are built with the sand containing little clay excavated from the Three Gorges Area; and four tests with different water level rising rates for each model are carried out. The model testing results indicate that the larger the rising water level rate, the more possible the bank fall. During rising water level, some factors advantaging or disadvantaging the bank stability may be induced by the interactions between the model soil mass and the ground water or reservoir water. In these factors, the vanishing of the capillary force induced by the rising water level is very important. The typical phreatic lines in the model slope obtained from the experiment are compared with those obtained from a published analytical solution. The comparison indicates that the published analytical solution may over-valuate the evaluation of the phreatic line.

Key words: bank caving, rising water level, homogeneous bank, phreatic line