强降雨触发浅层黄土滑坡的水文作用机制研究

发布时间：2019-04-19 01:56

【摘要】：边坡稳定性问题是工程建设中频繁研究的工程地质问题,黄土是具有水敏性‖的特殊土,我国黄土以其分布广、连续、地层完整、厚度大而著称。在黄土高原地区,黄土滑坡给该地区人民的生命财产安全带来严重危害,研究黄土滑坡在降雨条件下的水文作用机制对于浅层黄土滑坡机理及预警研究具有重要意义。本文通过在陕西泾阳南塬典型黄土分布地区进行人工削坡,利用水分计、张力计、雨量计等仪器综合监测了黄土边坡在天然与人工降雨条件下的水文作用过程,并结合室内试验及数值计算分析了该边坡的稳定性。本文主要内容如下:(1)通过在人工边坡坡上平台上放置的雨量计获得天然及人工降雨的实际雨量,通过在坡上平台、坡面及坡脚处埋设的水分计及张力计获得了不同深度处的水分、基质吸力变化情况,得到黄土边坡在天然和人工降雨条件下的水文作用过程及各个深度处原状土体的土水特征曲线。(2)通过开展原状土体的基本物理性质、水理特性的试验研究,获得土体的密度、含水率、渗透率等基本参数,并基于现场监测数据得到了土水特征参数曲线及渗透系数曲线,并与室内所得土水特征曲线进行了对比。(3)通过对不同深度的原状土体进行的天然和饱和含水率条件下的直剪试验,得到了两个不同含水率状态下的抗剪强度参数,并根据土水特征曲线及饱和含水率下的土体的抗剪强度指标对不同含水率下的抗剪强度进行估算。(4)利用Geostudio2007对黄土边坡的雨水入渗规律及边坡稳定性进行初步计算分析。
[Abstract]:Slope stability is a frequently studied engineering geological problem in engineering construction. Loess is a special soil with water sensitivity. China's loess is famous for its wide distribution, continuous, complete stratum and large thickness. In the Loess Plateau region, the loess landslide has brought serious harm to the people's life and property safety in this area. It is of great significance to study the hydrological mechanism of the loess landslide under the condition of rainfall for the study of the mechanism and early warning of the shallow loess landslide. In this paper, the hydrologic process of loess slope under natural and artificial rainfall is monitored synthetically by means of artificial slicing in typical loess distribution area of Jingyang, Shaanxi Province, by means of water content meter, tension meter, rainfall meter and other instruments, and the hydrologic process of loess slope under natural and artificial rainfall conditions is monitored comprehensively. The stability of the slope is analyzed by laboratory test and numerical calculation. The main contents of this paper are as follows: (1) the actual rainfall of natural and artificial rainfall is obtained by the rainfall meter placed on the artificial slope, and the actual rainfall is obtained by the platform on the slope. The changes of moisture and matrix suction at different depths were obtained by the water meter and tensimeter embedded at the slope surface and the foot of the slope. The hydrologic process of loess slope under natural and artificial rainfall conditions and the soil-water characteristic curves of undisturbed soil at various depths are obtained. (2) the basic physical and hydraulic properties of undisturbed soil are studied by experiments. The basic parameters such as soil density, water cut and permeability are obtained, and the soil water characteristic parameter curve and permeability coefficient curve are obtained based on the field monitoring data. And compared with the soil water characteristic curves obtained in the laboratory. (3) through the direct shear test under the condition of natural and saturated moisture content of undisturbed soil with different depth, the shear strength parameters under two different water content conditions were obtained. According to the soil-water characteristic curve and the shear strength index of soil under saturated water content, the shear strength under different water content is estimated. (4) the Rain Water infiltration law and slope stability of loess slope are calculated and analyzed by Geostudio2007.
【学位授予单位】：华北水利水电大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P642.22

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