地下水对库岸边坡稳定性的影响

针对库岸边坡在库水位陡降时易发生失稳破坏这一特点，分析了地下水引发库岸边坡失稳的机理，指出在地下水作用下，边坡岩土物理力学性质恶化、库水浮托力以及坡体内渗透力是影响库岸边坡稳定性的重要因素，给出了考虑地下水影响的库岸边坡稳定性计算公式。对三峡库区的某边坡工程进行了分析，结果表明：边坡岩土体介质因饱水软化作用，其滑动面的力学参数值降低；库水浮托力在某种程度上有利于边坡的稳定。当库水位陡降时，坡体内产生较大的渗透力是导致边坡失稳的一个很关键的原因。同时指出，在进行库岸边坡治理设计时，采取合理的防冲刷、反滤及疏导措施，能有效地降低地下水对边坡稳定性带来的消极影响。

Effect of groundwater on stability of slopes at reservoir bank

In allusion to the characteristic of easily losing stability for reservoir slopes when water level descending rapidly, the mechanism of losing stability resulting from ground water for reservoir slopes is analyzed. The important factors influencing the stability of reservoir slopes, such as decrease of physico-mechanical parameters, buoyancy and seepage force, are pointed out. The formulas for calculating the stability of reservoir slopes considering groundwater are given. A slope project in the Three Gorges is illustrated. The results show that the resisting force of potential sliding face decreases due to softening, that the buoyancy at a certain extent helps to enhance the stability of slopes, and that the seepage force in slope body is a key factor resulting in a slope losing its stability. In addition, for designing a slope project, it is necessary to adopt some reasonable measures effectively decreasing the disadvantageous influence of groundwater on the stability of slope, such as setting protecting, inversely filtrating and draining systems.