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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。
In order to study the influence of initial seepage field distribution on rainfall infiltration in slope soil, based on the calculation principle of saturated-unsaturated seepage flow, a finite element numerical simulation method, which can consider both saturated seepage and unsaturated seepage, The seepage field affects the rainfall infiltration process under the slope and carries out the simulation calculation. The results show that the response time of pore water pressure and moisture content, the time to reach the transient saturated zone are inversely proportional to the distance from the slope during the rainfall infiltration, and the length and amplitude of transient water saturation The rainfall intensity is proportional to the rainfall intensity; the time required for the dissipation of pore water pressure and water content in the transient saturated zone is proportional to the rainfall intensity after the rainfall stops, and the pore water pressure and water content first increase after the rainfall infiltration and transient saturation zones The pore water pressure and water content outside the infiltration area remained unchanged. The rainfall caused the pore water pressure and water content in the slope to increase, and the increase extent was directly proportional to the rainfall intensity. Under the same rainfall intensity , The greater the initial substrate suction is, the harder it is to infiltrate the rainwater. When the maximum initial substrate suction is the same and the distribution of the initial seepage field is different, the slope with equivalent distribution of the initial seepage field is less likely to infiltrate into the rainwater. , The appearance time, depth and area of the transient saturated zone are directly proportional to the rainfall intensity. After the rainfall stopped, the depth and area of the transient saturated zone gradually dissipated. The pore water pressure and moisture content Rainfall intensity distribution and transient saturation region, and is closely related to the maximum suction distribution pattern matrix initial seepage field, select the appropriate initial seepage field study is a prerequisite slope rainfall infiltration.