库水位涨落与降雨联合作用下滑坡地下水动力场分析

ANALYSIS ON HYDRODYNAMIC FIELD INFLUENCED BY COMBINATION OF RAINFALLAND RESERVOIR LEVEL FLUCTUATION

合理确定降雨和库水位变动联合作用下滑坡地下水动力场是库岸滑坡稳定性评价的关键。以三峡库区白衣庵滑坡为例,通过对多年降雨资料的概率分析和多种库水位调控的方案选择,建立了相应的降雨分析模型和库水位调控模型。在野外调查的基础上,确定了滑坡区的水文地质模型。将 3 个模型结合起来,提出了一种考虑降雨与库水位逐日变化的库岸地下水非稳定渗流场的计算模式。并从危险原则出发,采用卡明斯基有限差分方法对白衣庵滑坡进行了多种工况下的地下水位计算,从而确定了最危险地下水位及其发生概率。

Influenced by the combination of rainfall and reservoir level fluctuation, the determination of groundwater level in landslides is of great importance in assessing the stability of the landslides along reservoir. According to precipitation data from year 1957 to 1988 in Fengjie County in the Three Gorges reservoir area, the probability analysis is conducted by using the extreme distribution and the related rainfall model is developed. Considering the various adjustment of reservoir level in the Three Gorges, its adjustment model is given. In the two models, the rainfall and the change of reservoir level are considered by day in terms of practical situation. A method is then proposed accordingly to study the hydrodynamic field of unsteady fluid flow influenced by this combination. The hydrodynamic field of Baiyi'an landslide is analyzed by this method. Groundwater is calculated in various conditions, and the worst case and its probability are given by comparison.