Formation Mechanism Of Plasticity Index Of Xigeda Clay In Xichang

Atterberg limits which have direct correlation with physical and mechanical properties of soil are very important properties to measure and assess physical and mechanical of soil. In this paper, according to physical and mechanical properties of Xigeda formation clay in Xi Chang and basing on interaction mechanism theory of water-soil, through the validation experiments, the formation mechanism plasticity index of Xigeda formation clay in Xichang has been discussed, Specific works are as follows:(1) Physical and mechanical properties and water physical properties of Xigeda clay rocks are analyzed. Studies have shown that the Xichang Xigeda clay mineral composition of rocks in the clay mineral content is significantly lower than that of Xigeda clay rocks in Panzhihua region. They are lack of typical clay minerals, thereby enabling the physical and mechanical properties of Xigeda clay rocks in Xichang are different from that of Xigeda clay rocks in other parts.(2) The theory of water-soil interaction mechanisms is completely exposited. Influence factors on plasticity of fine-grained soil are summarized. Plasticity of fine-grained soil results in interaction of a variety of factors. The mineral composition and its fine-grained soil particles are mainly influence factors affecting the plasticity of fine-grained soil.(3) Through confirmatory tests, according to basic theory of the water-soil interaction mechanism, formation mechanism of plasticity index of Xigeda formation clay stone in Xichang has been explained. Main factors that influence the plasticity of Xigeda formation clay stone in Xichang are their clay minerals composition and grain size composition. The mineral composition of Xigeda clay mainly influence their plasticity through affecting thickness of diffusion double layer, grain composition mainly influences their plasticity through the capillary water, there is essential difference between the factors.