降雨入渗条件下炭质泥岩路堤动态稳定性
Dynamic stability of carbonaceous mudstone embankment under rainfall infiltration

为了研究炭质泥岩路堤在降雨入渗条件下的稳定性，在分析路堤稳定性影响因素的基础上，结合饱和？卜潜ズ蜕？流及稳定性分析基本理论，提出了一种能同时考虑路堤内部饱和度、孔隙水压力、渗透力、软化及非饱和效应的路堤稳定性分析方法，并利用该方法对降雨条件下路堤渗流场及稳定性的变化规律进行了数值计算。研究结果表明：提出的路堤稳定性动态计算方法具有较强的实用性，能够综合考虑多因素影响下的炭质泥岩路堤稳定性；降雨期间，炭质泥岩路堤内部地下水位逐渐抬升，饱和区渗透力合力先减小，后增大；降雨停止后，路堤内部地下水位迅速降低，饱和区渗透力合力逐渐减小；降雨条件下，炭质泥岩路堤坡面附近非饱和区土体的渗流速度与其孔隙水压力、饱和度变化成正比，饱和区土体沿路堤内部水平向外的渗流速度、渗透力与地下水位变化成正比，沿路堤上部竖直向下的渗流速度、渗透力与地下水位变化成反比；降雨过程中，炭质泥岩路堤安全系数先降低，再升高，后持续降低；降雨停止后，安全系数先迅速恢复，后趋于平缓；降雨初期，路堤饱和区塑性带先扩张，后消散，过坡脚的塑性带基本不变，降雨后期，路堤饱和区塑性带与过坡脚的塑性带均持续增加。降雨终止后，路堤饱和区塑性带与过坡脚的塑性带均逐渐消散。
In order to study the carbonaceous mudstone embankment stability under the condition of rainfall infiltration, this paper analyzed the factors influencing the stability of embankment, and proposed a stability analyzing method that can consider the saturation, pore water pressure, seepage force, soften and unsaturation effect. Combing the saturated？？unsaturated seepage and stability theory, this paper used the proposed method to calculate the changes of embankment seepage field and stability in rainfall condition. The results show that the dynamic stability calculation method presented in this paper has strong practicality, which can consider the stability of carbonaceous mudstone embankment influenced by multiple factors. During the period of rainfall, the underground water level inside the carbonaceous mudstone embankment rises gradually, the resultant force of penetration decreases first and increases later. After rain, the underground water level inside the embankment reduces rapidly, the resultant force of penetration decreases gradually. Under the condition of rainfall, the seepage velocity of soil in unsaturated zone near the carbonaceous mudstone embankment slope is directly proportional to the change of its pore water pressure and saturation, the seepage velocity and penetration force of soil in saturated zone along the inside of embankment horizontally outward is directly proportional to the change of the underground water level under embankment slope surface, the seepage velocity and penetration force of soil in saturated zone along the upper part of embankment vertically downward is inversely proportional to the change of the underground water level under embankment slope surface. In the process of rainfall, the stability safety factor of the carbonaceous mudstone embankment decreases first, then increases and continues to reduce again. After the rain, the stability safety factor first recovers quickly, then levels off. During the early period of rainfall, the plastic tape of saturated zone expands first and then dissipates, and