降雨对桂东南容县花岗岩残坡积土边坡影响分析与滑坡监测技术研究

发布时间：2018-03-29 10:19

本文选题：降雨　切入点：桂东南容县　出处：《广西大学》2017年硕士论文

【摘要】：桂东南容县花岗岩分布区的地质环境复杂脆弱,在充沛的降雨和日益加剧的人类工程活动激发作用下,该区域成为地质灾害的高易发县。为了掌握容县花岗岩分布区地质灾害的发育状况,以便为地质灾害的监测预警和防治规划提供科学依据,本文以桂东南花岗岩残坡积土边坡为重点研究对象,采用统计分析、野外人工降雨模拟试验和数值模拟分析相结合的研究方法,总结边坡的破坏类型与发育特征,分析边坡稳定性的主要影响因素;研究降雨对边坡稳定性的影响,分析各种降雨工况条件下降雨入渗过程中土体物理性质参数(含水率、孔隙水压力)与位移的变化特征,最后对滑坡监测技术进行了探讨。主要研究成果如下:(1)容县花岗岩残坡积土边坡破坏类型有四种:滑坡、崩塌、不稳定斜坡和泥石流,其中滑坡分布最广且数量最多,不稳定斜坡、崩塌数量次之,泥石流发育极少。(2)容县地质灾害发育与分布主要受地层岩性、工程特性、降雨与人类工程活动影响,其中,地层岩性、工程特性是影响边坡稳定性的主要内在因素,降雨和人类工程活动是影响边坡稳定性的主要外在诱发因素。(3)降雨入渗引起的土水作用体现为土体含水率的升高与孔隙水压力的波动剧烈,然而,粒度组成和降雨特征(历时与强度)会显著影响水土作用的进度。(4)边坡水平位移和垂直位移均随降雨强度和历时的增大而增大,其中水平位移主要在边坡浅表层变化,坡顶和坡脚处的水平位移变化量最大,且变化趋势由表层土向深处递减;垂直位移主要在坡顶变化。(5)降雨雨型对水平位移的影响依次为:递增型中强型递减型均匀型;在降雨量和降雨历时相同的条件下,4种降雨雨型对垂直位移的影响程度相同。边坡的变形以垂直位移为主。(6)桂东南地区滑坡变形与降雨量有明显的对应关系,季节性的变化比较明显,在雨季4～9月,位移增大明显,其他时段边坡趋于稳定。
[Abstract]:The geological environment in the granite distribution area of Rong County in southeast Guangxi is complex and fragile, which is stimulated by abundant rainfall and increasing human engineering activities. In order to understand the development of geological hazards in the granite distribution area of Rong County, this region can provide scientific basis for monitoring, early warning and prevention and control planning of geological hazards. In this paper, the granite residual slope soil slope in southeast Guangxi is taken as the main research object. The failure types and development characteristics of the slope are summarized by combining the statistical analysis, artificial rainfall simulation test and numerical simulation analysis in the field. This paper analyzes the main influencing factors of slope stability, studies the influence of rainfall on slope stability, analyzes the variation characteristics of soil physical properties parameters (water content, pore water pressure) and displacement during rainfall infiltration under various rainfall conditions. Finally, the monitoring technology of landslide is discussed. The main research results are as follows: there are four types of failure types of granite residual slope soil slope in Rong County: landslide, collapse, unstable slope and debris flow, in which landslide is the most widely distributed and has the largest number. The development and distribution of geological hazards in Rong County are mainly affected by stratigraphic lithology, engineering characteristics, rainfall and human engineering activities, among which stratigraphic lithology, Engineering characteristics are the main internal factors affecting slope stability. Rainfall and human engineering activities are the main external inducing factors affecting slope stability.) the soil-water action caused by rainfall infiltration is reflected in the increase of soil moisture content and the fluctuation of pore water pressure. The grain size composition and rainfall characteristics (duration and intensity) will significantly affect the progress of soil and water action. The horizontal displacement and vertical displacement of slope increase with the increase of rainfall intensity and duration, and the horizontal displacement mainly changes in the shallow surface layer of the slope. The change of horizontal displacement at the top and foot of the slope is the largest, and the variation trend decreases from the surface soil to the deep, the vertical displacement mainly changes in the top of the slope, and the effect of rainfall rain pattern on the horizontal displacement is as follows: increasing type, medium strong decline type, uniform type; Under the condition of the same rainfall and rainfall duration, the influence of four rainfall patterns on vertical displacement is the same. The slope deformation is mainly vertical displacement.; the landslide deformation in southeast Guangxi has obvious corresponding relationship with rainfall. The seasonal variation is obvious, during the rainy season from April to September, the displacement increases obviously, and the slope tends to be stable in other periods.
【学位授予单位】：广西大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU45

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