Analysis on Influence of Fall of Level to Stability of Dam Slope in Reservoir Area

For some special reasons, the reservoir would drains water to downstream with large discharge, so the reservoir water level would fall fast in a short time, the dissipation speed of pore water pressure in the dam is slower than the fall speed of water level, the excess pore pressure would be produced by the lagged effect of underground water level. Thus, the falling velocity of water level is an important influence factor to the slope stability. Taking No.1 Auxiliary Dam of Nanjindu reservoir, which is a heterogeneous core earth and rock-fill dams, as a projection example, numerical calculation method has been used to analyze the influence of water level fall speed to the dam slope stability, the dissipation rate of pore water pressure and the different parameters of soils also have been studied. The result shows that the level fall speed to the dissipation of pore water pressure and the dam slope stability are closely related, and through the control of level fall speed could improve the stability coefficient.