路基边坡的非均匀变形分析

Analysis on the Irregular Deformation of Some Subgrade Slope

某岩质路基边坡被１～２ｍ厚的砂粘土层覆盖，变形具有明显的非均匀性。边坡地下水水位的大幅度抬升是促进其显著变形的关键因素；变形的非均匀性是由地下水动态对降雨过程的迟钝的反应所决定的；地下水动态对降雨过程的敏感程度受控于土层的初始渗透性、降雨方式和降雨量；能够对地下水动态产生明显影响的降雨过程一般应同时满足以下三个条件；ａ．雨前经历过较长时间的炎热天气，土层蒸发强烈、初始渗透性良好；ｂ．降水过程以中到大雨开始，且持续较长时间；ｃ．降雨时间长，降水量大。本项研究对于被（砂）粘土层覆盖的岩质边坡的稳定性预测具有普遍意义。

Some rocky subgrade slope is covered by a layer of 1-2 m thick sandy clay, and its deformation is conspicuously irregular . The big margin rise of groundwater level is the key factor to the slope deformation and the irreguarity of the slope deformation is controlled by the obtuse reaction of the groundwater fluctuation to rainfall process. The sensitivity of the groundwater fluctuation to rainfall process is influenced by initial permeability of the sand clay layer , rainfall style and rainfall amount. The rainfall process which can make a remarkable influence on the groundwater fluctuation should satisfy the following requirements : a before rain the soil layer is intensely evaporated and its initial permeability is good b rainfall process begins with moderate rain or heavy rain and continue for a long time .c. the rainfall time is long and rainfall rate is great. The research achievements are important to the stability predication for the slopes covered by sandy clay layer.