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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-非饱和渗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 stability of carbonaceous mud embankment under the conditions of rainfall infiltration, based on the analysis of the factors affecting the stability of embankment and combining with the basic theory of saturated-unsaturated seepage and stability analysis, a method is proposed to consider the internal saturation of embankment Degree, pore water pressure, seepage force, softening and unsaturated effect of the embankment stability analysis method and the use of the method under the condition of rainfall in the seepage field and stability of the variation of the law of a numerical calculation. The results show that the proposed dynamic calculation method of embankment stability is of strong practicability and can comprehensively consider the stability of carbonaceous mudstone embankment under the influence of multiple factors. During the rainfall, the groundwater table inside the embankment of carbonaceous mudstone gradually rises, After the rainfall stopped, the groundwater table inside the embankment decreased rapidly and the seepage force in the saturated zone decreased gradually. Under rainfall, the seepage velocity of soil in the unsaturated zone near the embankment slope of carbonaceous mudstone and its The pore water pressure and saturation change are proportional to the seepage velocity and seepage force of saturated soil along the embankment, which is proportional to the change of groundwater level. The vertical seepage velocity, seepage force and groundwater level change along the upper embankment In the process of rainfall, the safety coefficient of embankment of carbonaceous mudstone firstly decreased, then increased and then decreased continuously. After the rainfall stopped, the safety factor firstly recovered quickly and then tended to be gentle. In the early stage of rainfall, the plastic zone of embankment saturated zone expanded first, Dissipated, the plastic zone over the foot of the foot remained unchanged, and the plastic zone of the plastic zone and the foot over the foot in the saturation area of the embankment continued to increase in the late rains. After the rainfall ended, the plastic zone in the saturated area of the embankment and the foot over the slope gradually dissipated.