Study On Static Characteristic Test Of Saline Soil In Lop Nur

In this paper, the typical crude saline soil along the railway from Kami to Lop Nur is selected. The static characteristics of the saline soil is studied through indoor static triaxial test. The triaxial drained and undrained consolidation shear tests with the control of dry density, moisture content and saturation state carries on using the strain-controlled type triaxial apparatus. And stress-strain relationship, volumetric-strain relationship, the influence of dry density and moisture content to shear strength index, and the change law of duncan-chang model parameters are analyzed.It is found from the test that, the sulphate and chlorine saline soil have the different drained and undrained consolidation shear test results by test.(1) The stress-strain behavior of chlorine saline soil with different dry density and saturation state, and sulphate salty soil with smaller dry density and different saturation state is classified into harden type, which presents contractive phenomenon. The sulphate salty soil in bigger dry density is classified into soften type, which presents phenomenon of shear dilatancy.(2) The structural strength of sulphate salty soil is harder than that of chlorine saline soil with the same dry density and saturation state. The stress strain curve of those two saline soils can divide into the phases of compaction deformation, elastic compression, yield deformation and destruction in the non-saturation state. Because of the high viscosity, the brine do not has compaction deformation phase in saturation state. The shear strength index of brine saturated samples is higher than that of in the non-saturation state.(3) The shear strength index of saline soil gets higher as the dry density increasing just the same as the non-salty-soil. The approximate linear relationship is shown between the shear strength index and dry density as the change of dry density. The duncan-chang model parameters are solved under different saturation states. The Rfof two saline soils are both larger. The initial tangent modulu of sulphate salty soil is higher than that of chlorine saline soil within the same dry density. It shows that the resistance capacity to deformation of sulphate salty soilis bigger than that of chlorine saline soil.(4) In the triaxial drained and undrained consolidation shear test, the stress-strain relationship presents softening-shear dilatation-partial shear dilatation mode in lower dry density. The stress-strain relationship presents hardening-shear dilatation-partial shear dilatation mode in higher dry density. The saline soil presents softening-shear dilatation-partial shear dilatation mode in different dry density. The shear strength index of sulphate salty soil is bigger than that of chlorine saline soil. It can be also seen that the structural strength of sulphate salty soil is higher than that of chlorine saline soil from the pore water dissipation law. The shear strength index of salty soil is increasing as the dry density increasing. The Change of moisture content has little influence towards the strength parameter of salty soil.