Study On Triaxial Tests Of Water Glass Solidified Sulphuric Acid Saline Soil

Saline soil is a special soil which is inexorable in the construction of Northwest China.The sulphate in the soil is so high in many areas,which brings buildings in danger.At present,the study of curing and improvement of sulphate soiled soil holds that the combination of water glass,lime and fly ash solidifying soiled soil has good effect on enhancing the strength of saline soil,strengthening the cementation strength of soil and inhibiting the expansion.In this paper,the stress-strain characteristics of water glass solidified sulphate saline soil were studied by triaxial tests,and the change law of three axis shear parameters was summarized.The curing mechanism was explained by scanning electron microscope test and acoustic test at the micro level,and the alkali excitation effect of water glass was explained.At the same time,seting the test of 14 days,28days and 60 days to discuss the effect of time on the three axis shear strength parameters of sodium silicate stabilized sulphuric saline soil.The main conclusions of this paper are as follows:(1)The stress-strain relationship of sulphate soil.The stress-strain curves of pure sulphuric acid saline soil samples belong to strain hardening,and lime and fly ash(two ash)solidified samples are stable,and water glass and two ash solidified samples are strain softening.The incorporation of sodium silicate causes the plasticity of saline soil to decrease,and the specimen exhibits brittle failure.The mechanism of sodium silicate and two ash combined solidification of sulfate soil was discussed from the microscopic perspective by SEM.(2)Effect of age on shear strength parameters of solidified saline soil samples.The shear strength of the sulfate soiled soil decreased with the age increasing,and the shear strength of the sulphate soiled soil after the lime + fly ash solidified first decreased and then increased with the age.When the concentration of water glass was low,the shear strength of the water glass and two ash cured soiled soil samples increased with the age,and the shear strength showed a decline.Potential;when the water glass concentration up to 40 DEG B,shear strength and age is not a linear relationship.(3)The influence of water glass concentration on the parameters of the three axis test.We put forward the concept of the contribution value of sodium silicate to the strength of saline soil,thus obtaining the effect of the concentration of sodium silicate on the strength of sulphate saline soil.The damage of three axis under the joint action of internal friction angle and cohesive force andthe analysis of the excitation effect of sodium silicate are discussed.