A Study of the Occurrence Mechanism, the Prediction and Prevention Works of Landslides by the Groundwater Flow Analysis

(1)屏蔽段观测井全长度内水质垂直分布是潜力最大的地下水通过井壁渗入井内并垂直扩散的结果。因此，钻孔内的水质分布与钻孔附近的地下水分布不一致。(2)通过数值分析和砂模型试验得出如下结论：在滑坡坡面等倾斜地流中，观测井内的水位在其全部长度上都有遮挡，与原来的地下水自由面不一致，而是出现在地下水自由面以下。(3)提出了一种简单的有限元方法来分析具有自由地表的稳定地下水流动。该方法适用于所有涉及非饱和区的区域，在非饱和区的水力导率恒定的条件下，无需网格迭代。该方法可以很容易地应用于涉及复杂边界和任意非均质程度的各种问题。利用这种方法，可以很容易地获得滑面孔隙水压力，这是滑坡边坡稳定性分析所必需的。(4)在滑坡边坡稳定性分析中，对于有倾斜无侧限水流和具有不同渗透性的多坡体的滑坡边坡，不应假定地下水压力的垂直分布是静态的。

(1) The vertical distribution of water quality in the observation borehole with a screened section along all its length is generated as the results that the groundwater having the highest potential infiltrates into the borehole through its wall and diffuses vertically. And therefore the distribution of water quality in the borehole disagrees with one of groundwater being adjacent to the borehole.(2) We obtained the following findings from the numerical analysis and the sand model experiments : In such inclined groundflow as one in landslide slopes the water level in the observation borehole having a screened section along all its length disagrees with but appears below the original free surface of groundwater.(3) A simple finite elements method analyzing steady groundwater flow with a free surface is proposed. This method is applied to all the region involving the unsaturated zone without mesh iteration under the condition of which the hydraulic conductivity is constant in the unsaturated zone. The method can be applied with ease to a wide variety of problems involving complex boundaries and arbitrary degrees of heterogenity. Owing to this method it will be very easier to obtain the pore water pressure along the slip surface which is necessary to the stability analysis of landslide slopes.(4) In the stability analysis the vertical distribution of the ground water pressure should not be assumed static in the landslide slopes which have inclined unconfined groundwater flow and which have -the multi-s, Lratums with different permeabilities.