Influences of soluble salt content on mechanical properties of Ili undisturbed loess
摘要
In order to reveal the loading collapse yield and moisture characteristics of the unsaturated Ili undisturbed loess, a series of net mean stress increase-decrease tests on control suction, suction increase-decrease tests on control net mean stress, consolidation shear tests on control net confining pressure and suction under different soluble salt contents are carried out by using the unsaturated soil triaxial apparatus. The effects of soluble salt content on the deformation, yield and moisture of the unsaturated Ili loess are studied. The results show that there is a critical value for salt content to improve the cementation between particles. There are the peak yield net mean stress and the peak yield shear stress between 14 and 20 g/kg of salt content, and the loading collapse yield curve and the shear yield curve are the maximum. The compressibility index and moisture change at the consolidation stage decrease with the increase of salt content. The influences of salt content on moisture are mainly in the transition region of soil water characteristic drying curve, but there are few effects on the suction increase yield curve. The unsaturated Ili loess can be yielded by being excessively salting and reducing suction.