库水位升降作用下大型土石混合体边坡流-固耦合特性及其稳定性分析

FLUID-SOLID COUPLING CHARACTERISTICS AND STABILITY ANALYSIS OF SOIL-ROCK MIXTURE SLOPE IN RISING AND DRAWDOWN OF RESERVOIR WATER LEVELS

以金沙江中游梨园电站坝前大型土石混合体边坡为例,基于精细地质结构模型,研究其在蓄水及库水位骤降过程中的流-固耦合及相应的稳定性变化特征。结果表明:蓄水初期边坡地表变形较为缓慢,当库水位达到某一高程时,其地表变形呈现陡增趋势;在蓄水初期边坡的稳定性有所下降,当上升至某一临界水位后边坡稳定系数达到最低值,而后随着库水位的上升有所回弹;库水位骤降对边坡稳定性影响较大,且其稳定系数下降随着骤降幅度的增大而增大。这些对于指导实际工程及深化库区土石混合体边坡的研究具有一定的理论意义。

Taking a soil-rock mixture slope in the middle reaches of Jinsha River for example, the fluid-solid coupling and stability characteristics during rising and drawdown of reservoir water levels are studied based on its fine geological structure model. The results indicate that during the initial impoundment period, the deformation of the ground surface is very slow, while the reservoir water level reaches certain elevation it exhibits a trend of sharp rise; the safety factor of the slope stability will decrease; and when the water level reaches a critical one it has the minimum value; hereafter it will rise with the water level rising; the sudden drawdown of the reservoir water level does affect the stability of the slope greatly; and the decreasing value of the safety factor will increase with the amplitude of the drawdown of the water level. All these results will be very useful not only for the practical engineering but also for the theoretical study of the soil-rock mixture slopes in reservoir area.