陕北地区降雨诱发黄土滑坡的机理研究

发布时间：2018-03-18 12:48

本文选题：黄土滑坡　切入点：降雨　出处：《西安建筑科技大学》2017年硕士论文　论文类型：学位论文

【摘要】：陕北地区是黄土滑坡的高发区,给当地人们的生活带来了无法想象的影响,同时也影响了当地的经济建设和各行各业的发展。我国岩土领域专家和学者在预防和治理黄土滑坡问题方面取得不菲的成绩,然而,关于陕北地区黄土滑坡与降雨的内在机理进行系统全面分析与研究的成果并不多见。随着陕北地区资源开发程度的提高和经济社会活动的加剧,黄土高原水土流失、土壤退化、生态恶化等环境问题日益突出,其中黄土滑坡问题愈加严重,预防和治理黄土滑坡问题,仍迫在眉睫。因此,本文以陕北黄土滑坡为研究对象,通过收集分析陕北地区的气象资料与地质条件,利用ABAQUS数值分析软件,分别从降雨强度、降雨持时、降雨类型及边坡类型四个方面进行边坡降雨入渗及稳定性分析,研究降雨与滑坡之间的内在联系,揭示降雨诱发滑坡的内在机理。并根据具体的黄土滑坡实例,进一步验证降雨诱发黄土滑坡机理的合理性,为减少该地区黄土滑坡提供科学依据。本文主要研究内容如下:(1)通过分析陕北地区的黄土滑坡资料与气象资料,获取该地区黄土滑坡和降雨的时空分布规律。根据陕北地区的地质构造及岩体特征,本文建立两种边坡模型:纯黄土边坡模型与黄土-红粘土边坡模型,根据陕北地区的黄土及红粘土的物理力学性质,选取合适的模型参数。(2)利用ABAQUS数值分析软件进行边坡降雨入渗分析,选取10mm/d、25mm/d、50mm/d、75mm/d及100mm/d五种不同强度的降雨,分别从降雨强度、降雨持时、降雨类型及边坡类型四个方面进行边坡降雨入渗研究。根据降雨模拟结果分别获得降雨强度、降雨持时、降雨类型及边坡类型与孔隙水压力的关系趋势线,并拟合出对应的数学表达式。(3)利用ABAQUS数值分析软件进行边坡稳定性分析,选取10mm/d、25mm/d、50mm/d、75mm/d及100mm/d五种不同强度的降雨,分别从降雨强度、降雨持时、降雨类型及边坡类型四个方面进行边坡稳定性研究。根据边坡稳定性模拟结果分别获得降雨强度、降雨持时、降雨类型及边坡类型与边坡失稳时的安全系数的关系趋势线,并拟合出对应的数学表达式。(4)选取陕北地区降雨诱发滑坡的典型实例,利用ABAQUS数值分析软件,建立边坡模型,赋予合理的参数,在降雨强度为15mm/d和降雨持时为10天的工况条件下,从降雨持时方面进行降雨入渗及稳定性分析,进一步验证降雨对滑坡的影响。根据模拟结果分别获得降雨持时与渗流速度及边坡失稳时的安全系数的关系趋势线,并拟合出对应的数学表达式。
[Abstract]:Northern Shaanxi is an area with a high incidence of loess landslides, which has had an unimaginable impact on the lives of local people. At the same time, it also affects the local economic construction and the development of various industries. Our country's experts and scholars in the field of rock and soil have made great achievements in preventing and controlling the loess landslide, however, There are few results of systematic and comprehensive analysis and research on the inherent mechanism of loess landslide and rainfall in northern Shaanxi. With the development of resources and the aggravation of economic and social activities in northern Shaanxi, soil erosion and soil degradation in loess plateau. Environmental problems such as ecological deterioration are becoming more and more prominent, among which loess landslide is becoming more and more serious. It is still urgent to prevent and control loess landslide. Therefore, this paper takes loess landslide in northern Shaanxi as the research object. By collecting and analyzing the meteorological data and geological conditions in northern Shaanxi, using ABAQUS numerical analysis software, the slope infiltration and stability are analyzed from four aspects: rainfall intensity, rainfall duration, rainfall type and slope type, respectively. The internal relationship between rainfall and landslide is studied, and the inherent mechanism of landslide induced by rainfall is revealed, and the rationality of the mechanism of landslide induced by rainfall is further verified according to the concrete examples of loess landslide. In order to provide scientific basis for reducing loess landslide in this area, the main contents of this paper are as follows: 1) by analyzing loess landslide data and meteorological data in northern Shaanxi, The temporal and spatial distribution of loess landslide and rainfall in this area is obtained. According to the geological structure and rock mass characteristics in northern Shaanxi, two slope models are established: the pure loess slope model and the loess-red clay slope model. According to the physical and mechanical properties of loess and red clay in northern Shaanxi, the appropriate model parameters. (2) the slope rainfall infiltration analysis was carried out by ABAQUS numerical analysis software. Five different rainfall intensities of 10 mm / d, 25 mm / d, 50 mm / d and 100 mm / d were selected, respectively, from the rainfall intensity. According to rainfall simulation results, rainfall intensity, rainfall duration, slope type and pore water pressure are obtained. The corresponding mathematical expression is fitted out. (3) the slope stability analysis is carried out by using ABAQUS numerical analysis software. Five kinds of rainfall of different intensity are selected: 10 mm / d 25 mm / d 50 mm / d 75 mm / d and 100 mm / d respectively from rainfall intensity and rainfall duration. The slope stability is studied in four aspects: rainfall type and slope type. According to the results of slope stability simulation, the trend lines of relationship between slope safety factor and rainfall intensity, rainfall duration, rainfall type and slope type are obtained. Fitting the corresponding mathematical expression. 4) selecting the typical example of landslide induced by rainfall in northern Shaanxi, using ABAQUS numerical analysis software, the slope model is established, and the reasonable parameters are given. Under the condition that the rainfall intensity is 15 mm / d and the rainfall duration is 10 days, the rainfall infiltration and stability are analyzed from the point of rainfall duration. According to the simulation results, the relationship between rainfall duration, seepage velocity and slope safety factor is obtained, and the corresponding mathematical expression is obtained.
【学位授予单位】：西安建筑科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU444;P642.22

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