Study On Rainfall Penetration And The Response Of Shear Strength Of Unsaturated Red Clay

This thesis subject on the characteristics of rainwater penetrating into typical unsaturated red loam in Jiangxi province. Based on the previous researches of landslide disaster mechanism under rainfall conditions and disaster-solving measures, this paper combining with the related strength of unsaturated soil mechanics theory to explore a series of scientific problems----unsaturated red loam infiltration characteristics under the rainfall condition, various factors on unsaturated red loam soil-water characteristic curve effects and the strength changes of unsaturated red loam after rainfall infiltration. Furthermore,the author of thesis has designed three kinds of experiment----unsaturated red red soil infiltration experiment, unsaturated red loam soil-water characteristic experiment and strength characteristics of unsaturated red loam experiment----to study the subject. The specific research arrangements are as follows:(1) By using the self-designed penetration testing device, the author of this thesis has carried out four different sets of unsaturated red loam rainfall penetration tests to analyze the factors on unsaturated red loam penetration from the view of unsaturated soil water content, dry density, penetrating time and time for precipitating.(2) By remodeling the red loam samples using FLSY-10 type of stress and strain controlled triaxial apparatus for unsaturated soil,the author of this thesis has implemented unsaturated soil-water characteristic curve test, analyzed the relationship between matric suction and water content, analyzed the factors of initial moisture content(saturation) and initial dry density on soil-water characteristic curve. Besides, the soil-water characteristic curve has been drawn with a lot of data to support the case, which has laid the foundation for further revealing the strength of unsaturated red loam attenuation.(3) Having implemented reshaping red loam saturated, unsaturated triaxial tests, combined with previous studies, the author of this thesis built a mathematical model of the relationship between matric suction and cohesion under the unsaturated condition by using the Origin software.(4) Based on the achievements of previous studies and reading the relevant information of soil landslide presented measures, the author of this thesis has put forward red earth soil slope slip measures and explored the contents of the landslide disaster prevention emergency plan, which can offer a reference for the landslide disaster prevention.