降雨入渗对边坡暂态饱和区分布特征的影响

发布时间：2018-06-19 16:55

本文选题：道路工程 + 暂态饱和区　；参考：《中国公路学报》2017年01期

【摘要】：针对降雨入渗形成的边坡内部暂态饱和区的形成与分布受多种因素影响的状况,开展了降雨条件下暂态饱和区形成条件及多因素影响下暂态饱和区分布的研究。基于有限元数值模拟方法,开展一维渗流及二维渗流过程计算,得到了暂态饱和区的形成条件及多因素影响下的分布特征。研究结果表明:一维渗流条件下,暂态饱和区生成速度和扩展范围受到降雨强度与降雨时间共同控制,暂态饱和区形成的根本原因是土体表面入渗流速大于土体内部湿润锋出渗流速;降雨条件下,暂态饱和区形成的速度为边坡下部大于边坡上部,降雨停止后,随着雨水的持续下渗,坡面已饱和区域体积含水率随着雨水的下渗逐渐降低,消散速度为边坡上部快于下部;降雨强度、初始边坡表面吸力、边坡土体类型对暂态饱和区形成时间、分布深度将产生一定的影响,且影响程度大于坡比对暂态饱和区的影响;在边坡初始表面吸力相同的条件下,降雨强度越大边坡表面孔隙水压力上升速度越快,在降雨强度相同的条件下,初始表面吸力越大边坡表面孔隙水压力上升速度越快,边坡表面孔隙水压力受坡比影响较小。
[Abstract]:In view of the fact that the formation and distribution of transient saturated zone in slope formed by rainfall infiltration is affected by many factors, the formation conditions of transient saturated zone and the distribution of transient saturated zone under the influence of multiple factors are studied. Based on the finite element numerical simulation method, the one-dimensional and two-dimensional seepage processes are calculated, and the formation conditions of the transient saturated region and the distribution characteristics under the influence of multiple factors are obtained. The results show that under the condition of one-dimensional seepage, the formation speed and expansion range of transient saturated zone are controlled by both rainfall intensity and rainfall time. The basic reason for the formation of transient saturated zone is that the surface infiltration velocity of the soil is greater than that of the moist front and exit seepage velocity of the soil, and under the condition of rainfall, the formation speed of the transient saturated zone is greater than that of the upper part of the slope, and after the rainfall stops, With the continuous infiltration of Rain Water, the volume water content of saturated area gradually decreases with the infiltration of Rain Water, and the dissipation speed is that the upper part of the slope is faster than the lower part, the rainfall intensity, the initial surface suction of the slope, The soil type of slope has a certain influence on the formation time and distribution depth of the transient saturated zone, and the influence degree is greater than that of the slope ratio, under the condition of the same initial surface suction of the slope, the influence of the slope soil type on the transient saturation zone is greater than that of the slope ratio. The higher the rainfall intensity, the faster the surface pore water pressure rises. Under the condition of the same rainfall intensity, the larger the initial surface suction, the faster the surface pore water pressure rises, and the less the slope surface pore water pressure is affected by slope ratio.
【作者单位】：长沙理工大学土木与建筑学院;法国国家科学研究院微观结构与材料力学实验室;长沙理工大学交通运输工程学院;现代公路交通基础设施先进建养技术湖南省协同创新中心;
【基金】：国家自然科学基金项目(51508040,51578079,51678073,51678074) 湖南省自然科学基金项目(2016JJ3010) 长沙理工大学土木工程重点学科创新性项目(15ZDXK08)
【分类号】：TU43

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