降雨入渗条件下炭质泥岩路堤动态稳定性

发布时间：2018-03-17 10:23

本文选题：道路工程　切入点：炭质泥岩路堤　出处：《长安大学学报(自然科学版)》2017年01期 　论文类型：期刊论文

【摘要】：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。
[Abstract]:In order to study the stability of carbonaceous mudstone embankment under the condition of rainfall infiltration, based on the analysis of the influencing factors of embankment stability, the basic theory of saturated-unsaturated seepage flow and stability analysis is combined. A method for stability analysis of embankment is proposed, which can take into account the internal saturation, pore water pressure, permeability, softening and unsaturated effects. By using this method, the seepage field and stability of embankment under rainfall are numerically calculated. The results show that the proposed dynamic calculation method of embankment stability has strong practicability. The stability of carbonaceous mudstone embankment can be considered comprehensively. During rainfall, the underground water level of carbonaceous mudstone embankment gradually rises, and the permeability of saturated area decreases first, then increases; The seepage velocity of soil in unsaturated area near the slope of carbonaceous mudstone embankment is proportional to the change of pore water pressure and saturation under the condition of rainfall. The seepage velocity of soil in saturated area along the road embankment is proportional to the change of groundwater level, the vertical and downward percolation velocity along the upper part of the embankment is inversely proportional to the change of underground water level; in the process of rainfall, the seepage force is inversely proportional to the change of underground water level. The safety factor of the carbonaceous mudstone embankment first decreases, then increases, then continues to decrease; after the rainfall stops, the safety coefficient quickly recovers, then tends to smooth; at the beginning of the rainfall, the plastic zone in the saturated area of the embankment expands first, then dissipates. The plastic zone of embankment saturation zone and the over slope foot continue to increase in late rainfall. After the end of rainfall, the plastic zone of embankment saturated zone and the slope foot gradually dissipate.
【作者单位】：长沙理工大学道路结构与材料交通行业重点实验室;长沙理工大学交通运输工程学院;长沙理工大学土木与建筑学院;
【基金】：国家自然科学基金项目(51578079,51508040,51678074,51378082) 湖南省自然科学基金项目(2016JJ3010) 湖南省研究生科研创新项目(kfj150305) 长沙理工大学道路结构与材料交通行业重点实验室开放基金项目(CX2016B383)
【分类号】：U416.12

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