Mechanical properties of Ili salinized loess under freeze-thaw conditions
In order to study the influence of factors such as the number of freeze-thaw cycles,confining pressure,and salt content on the mechanical properties of salinized loess in Ili,triaxial tests of salinized loess under the action of indoor freeze-thaw cycles were carried out.The deterioration mechanism of salinized loess after freeze-thaw and salt erosion was analyzed,and the strength deterioration formula and constitutive model of salinized loess were proposed.The results show that the increase of salt makes the stress-strain curve shift from softening type to hardening type under the action of freeze-thaw cycles.When the salt content is higher,the shear strength of loess decreases rapidly with the increase of the number of freeze-thaw cycles.The cohesion is exponentially related to the number of freeze-thaw cycles.The internal friction angle shows an increase and then a decrease with the increase in the number of freeze-thaw cycles and decreases with the increase in salt content.A degradation model of cohesion under freeze-thaw is established,which can predict the degradation characteristics of cohesion in specimens with different salt contents.The weight of the freeze-thaw effect on cohesion degradation is greater than that of salt corrosion.A modified Duncan-Chang model with multi-factors is proposed,which can more accurately reflect the strength and deformation characteristics of salinized loess after freeze-thaw and salt erosion.
soil mechanicssalt contentstress-straindeterioration modelDuncan-Chang model
NETL
NSTL
万方数据
