Study on the Composition of Unsaturated Q3 Loess by X-Ray

Collapsibility is the main factor affecting the microstructure characteristics of Q3 loess. The main chemical components in soil samples were determined by X-Ray experiment, and the main percentage of each component was calculated. Which is mainly composed of quartz, accounting for about 64.18% of the total chemical composition, there are also a large number of calcium and magnesium components in loess. Most of these calcium and magnesium exist in yellow soil in the form of calcite and dolomite. The surface soil sample contains a lot of soluble salt, the common soluble salts of Q3 loess are KCl, K2SO4, K2CO3, KNO3, NaCl, Na2SO4, Na2CO3, etc. It dissolved easily after meeting water, which is the key cause of significant changes in soil properties. The results showed that Q3 loess contains a lot of soluble salts, which change the microstructure of soil mass after meeting water, resulting in the reduction of soil strength; The content of soluble salt in Q3 loess is one of the fundamental reasons for the collapsibility of soil.