扬州地区粘性土土水特征曲线试验研究及其应用

发布时间：2018-06-12 20:48

本文选题：非饱和土 + 土水特征曲线　；参考：《扬州大学》2014年硕士论文

【摘要】：土-水特征曲线(SWCC)是关于非饱和土的一个重要本构关系,它表述了土中含水率与吸力之间的相互关系。非饱和土的很多基本特性,例如渗透性、持水系数、抗剪强度等都可以土-水特征曲线中推测得出,因此土水特征曲线对于研究非饱和土非常重要。本文以扬州地区典型粉质黏土和软黏土为研究对象,利用GDS非饱和三轴仪,进行土水特征曲线试验研究,并利用试验所得的土水特征曲线进行降雨入渗条件下的边坡稳定性分析,主要内容为： (1)对前人有关土水特征曲线研究成果进行了总结,总结了土水特征曲线试验方法、影响因素以及数学模型。 (2)利用GDS进行土水特征曲线测量试验,并比较分析了围压、干密度以及土质对土水特征曲线规律的影响,结果表明：围压对土水特征曲线影响不大；干密度越大,进气值越大,脱水速率越小；土体黏粒含量越大,进气值越大,脱水速率越小。 (3)采用Fredlund和Xing三参数数学模型对扬州地区黏性土土水特征曲线进行模拟,并给出相应的参数范围。 (4)基于室内试验得到的土水特征曲线方程,对降雨入渗条件下扬州地区黏性土边坡进行稳定性分析,结果表明：由土水特征曲线可知,同等基质吸力下,非饱和土体积含水率越大,渗透系数越大；一般情况下,土体进气值越大,同等基质吸力下渗透系数越大,边坡越稳定；扬州地区黏性土体遭遇特大暴雨时,降雨4天后边坡安全系数下降30%-50%,滑动面位于边坡表层。
[Abstract]:The soil-water characteristic curve (SWCC) is an important constitutive relation of unsaturated soil, which describes the relationship between soil moisture content and suction. Many basic properties of unsaturated soil, such as permeability, water-holding coefficient and shear strength, can be inferred from soil-water characteristic curve, so soil-water characteristic curve is very important to study unsaturated soil. In this paper, the typical silty clay and soft clay in Yangzhou area are taken as the research objects, and the characteristic curves of soil and water are tested by GDS unsaturated triaxial apparatus. The stability of slope under rainfall infiltration is analyzed by using the soil-water characteristic curve. The main contents are as follows: 1) the research results of soil and water characteristic curve are summarized. The test method, influencing factors and mathematical model of soil-water characteristic curve are summarized. (2) GDS is used to measure soil-water characteristic curve, and the effects of confining pressure, dry density and soil quality on soil-water characteristic curve are compared and analyzed. The results show that the confining pressure has little effect on the soil-water characteristic curve, the larger the dry density, the greater the inlet air value and the smaller the dehydration rate, the larger the clay content, the greater the inlet air value. The smaller the dehydration rate is, the smaller the dehydration rate is. The Fredlund and Xing three-parameter mathematical models are used to simulate the characteristic curves of clay soil and water in Yangzhou area, and the corresponding parameter ranges are given. The stability of clay soil slope in Yangzhou area under rainfall infiltration condition is analyzed. The results show that under the same matrix suction, the larger the volume moisture content of unsaturated soil is, the greater the permeability coefficient is. The larger the air intake value of the soil is, the greater the permeability coefficient is under the same matrix suction, and the more stable the slope is; when the viscous soil in Yangzhou region encounters heavy rain, the safety factor of the slope decreases by 30% -50% after 4 days of rainfall, and the sliding surface is located on the surface of the slope.
【学位授予单位】：扬州大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU41;TU442

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