降雨条件下镇江地区非饱和膨胀土边坡稳定性研究
发布时间：2018-07-16 11:31
【摘要】：膨胀土边坡失稳问题已经成为膨胀土地区的一个主要工程地质难题,引起了越来越多专家学者的关注,国内外学者对非饱和膨胀土边坡已经做了大量研究。现有研究普遍认为膨胀土边坡的安全系数随降雨的发展不断降低,而在镇江地区,大量的工程实践表明在降雨初期,随着降雨量的增大,边坡的安全系数有一个增大的过程,降雨量进一步增大,边坡安全系数逐渐减小。本文即通过室内试验、FLAC软件分析,研究镇江地区膨胀土边坡在降雨初期其安全系数的变化规律及其机理,得到边坡在降雨初期的稳定安全时间,为本地区的边坡地质灾害预警预报提供参考。本文主要研究内容如下:(1)通过室内试验:得到了膨胀土的抗剪强度与含水率的关系,即随含水率的增加抗剪强度呈先增加后减小的趋势。(2)通过对降雨入渗下的膨胀土边坡的稳定性进行数值模拟分析,发现了膨胀土边坡在降雨入渗条件下,边坡安全系数会有短暂增加的现象;(3)针对镇江地区在长时弱降雨和短时强降雨的降水特征,通过模拟分析,指出了膨胀土边坡发生失稳破坏的安全时间。
[Abstract]:The instability of expansive soil slope has become a major engineering geological problem in expansive soil area, which has attracted more and more attention of experts and scholars, and scholars at home and abroad have done a lot of research on unsaturated expansive soil slope. It is generally believed that the safety factor of expansive soil slope decreases with the development of rainfall. However, in Zhenjiang area, a large number of engineering practices show that the safety factor of expansive soil slope increases with the increase of rainfall at the beginning of rainfall. With the increase of rainfall, the slope safety factor decreases gradually. In this paper, through the analysis of FLAC software in laboratory test, the variation law and mechanism of the safety factor of expansive soil slope in Zhenjiang area at the beginning of rainfall are studied, and the stable and safe time of slope in the early stage of rainfall is obtained. It provides a reference for the early warning and forecast of slope geological hazard in this area. The main contents of this paper are as follows: (1) through laboratory tests, the relationship between shear strength and moisture content of expansive soil is obtained. That is, the shear strength increases first and then decreases with the increase of moisture content. (2) through the numerical simulation analysis of the stability of expansive soil slope under rainfall infiltration, it is found that the expansive soil slope under rainfall infiltration condition, The slope safety factor will increase temporarily. (3) according to the precipitation characteristics of long term weak rainfall and short term strong rainfall in Zhenjiang area, the safe time of instability and failure of expansive soil slope is pointed out by simulation analysis.
【学位授予单位】：江苏科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU43
本文编号：2126249
[Abstract]:The instability of expansive soil slope has become a major engineering geological problem in expansive soil area, which has attracted more and more attention of experts and scholars, and scholars at home and abroad have done a lot of research on unsaturated expansive soil slope. It is generally believed that the safety factor of expansive soil slope decreases with the development of rainfall. However, in Zhenjiang area, a large number of engineering practices show that the safety factor of expansive soil slope increases with the increase of rainfall at the beginning of rainfall. With the increase of rainfall, the slope safety factor decreases gradually. In this paper, through the analysis of FLAC software in laboratory test, the variation law and mechanism of the safety factor of expansive soil slope in Zhenjiang area at the beginning of rainfall are studied, and the stable and safe time of slope in the early stage of rainfall is obtained. It provides a reference for the early warning and forecast of slope geological hazard in this area. The main contents of this paper are as follows: (1) through laboratory tests, the relationship between shear strength and moisture content of expansive soil is obtained. That is, the shear strength increases first and then decreases with the increase of moisture content. (2) through the numerical simulation analysis of the stability of expansive soil slope under rainfall infiltration, it is found that the expansive soil slope under rainfall infiltration condition, The slope safety factor will increase temporarily. (3) according to the precipitation characteristics of long term weak rainfall and short term strong rainfall in Zhenjiang area, the safe time of instability and failure of expansive soil slope is pointed out by simulation analysis.
【学位授予单位】：江苏科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU43
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，本文编号：2126249
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