Artificial Preparation And Experiment Study On Physical And Mechanics Properties Of Hanzhong Expansive Soil

With the national attention to the landslide disaster of the expansive soil land area, the problem of Expansive soil is becoming more and more highlighted, and more and more experts devote their most time to the research on expansive and mechanical properties of expansive soil. The purpose of this study was to provide a solid theoretical foundation for the study of the micro pile reinforced expansive soil landslide in laboratory. So this paper mainly focus on the experimental study of the mechanical properties of expansive soil in Hanzhong area. Because the indoor similar simulation study of expansive soil landslide need a lot of expansive soil. And if the laboratory takes expansive soil from the expensive soil area, there will be a great challenge to the expansive soil and slide similar simulation research. In order to solve this problem, the method to get the soil that is similar to the properties of expansive soil in Hanzhong area is analyzed and studied in this paper.This paper takes Hanzhong expansive soil in Mianxian area as the research object, and outlines research status of expansion mechanism, microstructure and strength of expansive soil at home and abroad. Through indoor soil test, basic physical indexes of expansive soil in Hanzhoung area were measured, and analyzed the basic physical properties of expansive soil. Furthermore, this paper explored the relationship between the degree of compaction and shear force of expansive soil, and the relationship between the degree of compaction and shear strength index, and the relationship among the degree of compaction, free swelling quantity with side limit and expansive force under different vertical pressure. Under the condition of dry and wet cycle, this paper studied and analyzed the influence of wetting-drying cycle on shear strength of expansive soil, and the influence degree on the shear strength under the variation of moisture ratio in each cycle of dry and wet process, and the influence on the shear strength index and unconfined compressive strength and expansion with the change of the number of drying-wetting cycle. In order to provide convenient for the similar simulation test of expansive soil landslide, this paper explores artificial preparation method of expansive soil to achieve the artificial preparation of expansive soil as similar as Hanzhong’s expansive soil in lab. Through the analysis on the content and sort of expansion minerals contained in the original expansive soil. Compounding the common loess and the expansion minerals in a certain proportion makes up a artificial soil sample. Mensurating the Basic physical indexes of the artificial soil sample and analyzing free swelling quantity with side limit, Shear strength, shear strength index, gets all sorts of mechanical properties date on expansive soil. And compared with the experimental data corresponding to the original expansive soil in order to judge the effect of preparation expansive soil with different mixture ratio. Preparation of expansive soil optimum proportion is 31.22% Illite, Kaolinite and Chlorite is 9.32%,2%, Bentonite is 10%.