考虑初始渗流场影响的坡积土边坡降雨入渗过程

发布时间：2018-01-14 06:18

本文关键词：考虑初始渗流场影响的坡积土边坡降雨入渗过程　出处：《长安大学学报(自然科学版)》2017年05期 　论文类型：期刊论文

【摘要】：为了研究初始渗流场的分布对坡积土边坡降雨入渗的影响,基于饱和-非饱和渗流计算原理,采用能同时考虑饱和渗流与非饱和渗流的有限元数值模拟方法,分别对4种初始渗流场影响下边坡的降雨入渗过程进行了模拟计算。研究结果表明:降雨期间,入渗影响区内孔隙水压力、含水率的响应时间、达到暂态饱和区的时间与距坡面的距离成反比,进入暂态饱和区的长度及增大幅度与降雨强度成正比;降雨停止后,暂态饱和区内孔隙水压力、含水率消散所需时间与降雨强度成正比,入渗影响区与暂态饱和区之间孔隙水压力、含水率先增大后缓慢降低,入渗影响区外孔隙水压力、含水率保持不变;降雨引起边坡内部孔隙水压力及含水率的增大,增大幅度与降雨强度呈正比例关系,在降雨强度相同的条件下,初始基质吸力越大,雨水入渗难度越大;在最大初始基质吸力相同,而初始渗流场的分布形式不同时,初始渗流场水平等值分布的边坡更不易于雨水入渗;降雨过程中,暂态饱和区出现时间、深度及面积与降雨强度成正比,降雨停止后,暂态饱和区深度及面积逐渐消散,边坡内部孔隙水压力、含水率、暂态饱和区的分布与降雨强度、初始渗流场最大基质吸力以及分布形式密切相关,选择合适的初始渗流场是进行边坡降雨入渗过程研究的前提条件。
[Abstract]:In order to study the influence of the distribution of the initial seepage field of slope soil slope under rainfall infiltration, the calculation principle of saturated unsaturated seepage based on the finite element simulation method considering saturated seepage flow and unsaturated seepage numerical models of 4 slope influence the initial seepage field under rainfall infiltration processes were simulated the results show that the rainfall. During the infiltration zone of pore water pressure, the response time of the moisture content, reach the transient saturated zone time is inversely proportional to the distance from the surface, into the transient saturated zone length and increases with rainfall intensity is proportional to the rainfall; stop after transient saturation of pore water pressure in the region. Moisture dissipation time required is proportional to the intensity of rainfall, the infiltration influence between the region and the transient saturated zone of pore water pressure, water content increased first and then decreased slowly, the infiltration influence outside the pore water pressure, moisture keeping The same rainfall increased the slope; internal water pressure and pore water rate increases, and the rainfall intensity is proportional to the intensity of rainfall, in the same conditions, the greater the initial matric suction, rainwater infiltration more difficult; in the same maximum initial matric suction, and the distribution pattern of initial seepage field and initial slope the seepage field distribution of equivalent level is less prone to rain infiltration; rainfall, transient saturated zone time, area and depth with rainfall intensity is proportional to the rainfall stops, transient saturated zone depth and area of slope gradually dissipated, pore water pressure, water content, saturation distribution and rainfall intensity, initial the seepage field is closely related to the maximum suction and distribution form, select the appropriate initial seepage field in the slope under the condition of infiltration process research.

【作者单位】：长沙理工大学特殊环境道路工程湖南省重点实验室;长沙理工大学交通运输工程学院;洛林大学微观结构与材料力学实验室;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(51678073,51508042,51678074,51508040) 湖南省重点研发计划项目(2016SK2023) 长沙理工大学特殊环境道路工程湖南省重点实验室开放基金项目(kfj140501) 浙江省交通运输厅科研计划项目(2014H22)
【分类号】：U416.14
【正文快照】： 0引言大量边坡失稳统计资料表明,降雨是导致边坡失稳的主要环境因素之一[1-2]。当前已有不少学者对降雨条件下边坡稳定性的失稳机制进行了探讨。一般而言,降雨会引起边坡内部土体的含水率和地下水位上升,从而导致边坡内部土体的重度、孔隙水压力和渗透力逐渐增大,从而引起坡体

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