含裂隙土质边坡渗流规律的解析模型研究

发布时间：2018-06-01 02:04

本文选题：渗流 + 二维　；参考：《成都理工大学》2017年硕士论文

【摘要】：在地震动作用过后的土质边坡失稳的案列之中发现了很多由于降雨导致的坡体失稳现象。很多学者对此类型的边坡失稳现象做出了大量的研究发现导致坡体失稳的主要原因是由于地震动作用后破体内部存在有大量的裂隙,这些裂隙的存在成为了水分运移的通道,从而使得土体力学性质迅速降低,最终导致坡体失稳。前人对于一维饱和-非饱和渗流解析解的研究已经比较成熟,但由于在求解二维饱和-非饱和渗流公式解析解时,边界条件过于的复杂,不便于求解,所以现阶段对二维的饱和-非饱和渗流的研究基本上是依赖于物理实验以及数值模拟来进行研究。本文在前人一维饱和-非饱和渗流公式解析解的研究基础上,将一维的饱和-非饱和渗流公式解析解拓展到二维的饱和-非饱和含裂隙均质土渗流的解析解,为研究二维饱和-非饱和渗流提供一种新的理论方法。再通过对不同情况下含裂隙土和含裂隙土质边坡饱和-非饱和渗流公式进行解析求解,通过解析求解得出的孔隙水压力变化曲线,探讨不同裂隙模式情况下对含裂隙土体及土质边坡渗流的影响规律。本文的主要研究内容集中在以下两个方面:(1)对一维饱和-非饱和渗流公式解析解做了进一步拓展,建立了二维饱和-非饱和含裂隙土渗流解析模型,并推导出了二维渗流控制方程的显式解析解;(2)本文通过二维渗流解析模型,详细讨论了降雨条件下,不同裂隙模式(裂隙深度、裂隙发育位置及裂隙密集程度)对土体及坡体渗流的影响规律。研究发现裂隙深度的变化对土体及坡体降雨入渗的影响极其巨大,随着裂隙深度增加降雨的入渗深度几乎成倍数的增加。而坡体裂隙降雨入渗情况不同于土体,在降雨入渗的初期由于坡体部位的土体相对于坡顶部位的较薄,所以水分是最先向斜坡部位开始移动,从而导致在在降雨初期坡顶部位孔隙水压力还存在相对减小的现象。土体及坡体裂隙的发育宽度和发育数量变化对降雨入渗深度影响相对比较轻微,几乎不发生变化。
[Abstract]:A lot of slope instability phenomena caused by rainfall have been found in the sequence of soil slope instability after ground motion. Many scholars have done a lot of research on this kind of slope instability phenomenon and found that the main cause of slope instability is that there are a large number of cracks in the broken body after ground motion, and the existence of these cracks has become the channel of water migration. Therefore, the mechanical properties of soil are reduced rapidly and the slope is unstable. The previous researches on the analytical solution of one-dimensional saturated-unsaturated seepage flow have been mature, but the boundary conditions are too complicated to be solved because of the complexity of solving the analytical solution of two-dimensional saturation-unsaturated seepage equation. So the study of two-dimensional saturated-unsaturated seepage basically depends on physical experiments and numerical simulation. In this paper, based on the study of the analytical solution of the one-dimensional saturated-unsaturated seepage flow formula, the analytical solution of the one-dimensional saturation-unsaturated seepage equation is extended to the two-dimensional analytical solution of the saturated unsaturated fractured homogeneous soil seepage. It provides a new theoretical method for the study of two dimensional saturated-unsaturated seepage. Then the saturated unsaturated seepage formula of fractured soil and fractured soil slope is solved analytically, and the pore water pressure variation curve is obtained by analytic solution. The influence of different fracture modes on seepage of fractured soil and soil slope is discussed. The main research contents of this paper are as follows: 1) the analytical solution of one-dimensional saturated-unsaturated seepage equation is further expanded, and a two-dimensional saturated unsaturated fractured soil seepage analytical model is established. The explicit analytical solution of the governing equation of two-dimensional seepage flow is derived in this paper. Through the analytical model of two-dimensional seepage flow, the different fracture modes (depth of fracture) under rainfall condition are discussed in detail. The influence of fracture development position and fracture density on seepage of soil and slope. It is found that the variation of fracture depth has great influence on the rainfall infiltration of soil and slope, and the infiltration depth of rainfall increases almost multiple with the increase of fracture depth. In the early stage of rainfall infiltration, because the soil of slope body is thinner than that of the top of slope, the water is moved to the slope first. As a result, the pore water pressure at the top of the slope decreases relatively at the early stage of rainfall. The variation of the width and quantity of cracks in soil and slope body has little effect on the depth of rainfall infiltration.
【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU43

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