Experimental study on plane strain of frozen silty clay under different minor principal stresses and negative temperatures
Aiming at the plane strain problem in freezing method construction,the plane strain tests were carried out by using the improved true triaxial apparatus of frozen soil in Anhui University of Science and Technology.Subsequently,the strength and deformation of frozen silty clay were analyzed under different principal stresses and temperatures.Based on Weibull distribution and Drucker-Prager strength criterion,a damage constitutive model was established for frozen silty clay.The theoretical and experimental results demonstrate that the stress-strain curves under different minor principal stress exhibit different degrees of hardening characteristics at the same negative temperature.The failure strength increases first and then decreases with the increase of the minor principal stress,while it increases linearly with decreasing temperature.The established nonlinear Mohr-Coulomb strength criterion can describe the nonlinear correlation between the strength of frozen silty clay and the minor principal stress.Under different test conditions,the strain along the minor principal stress is expansion deformation,and the volume strain exhibits shear contraction.As the minor principal stress increases,the deformation modulus of the sample increases first and then decreases.For the same minor principal stress,the deformation modulus exhibits a negative correlation with temperature.Under the same temperature,the intermediate principal stress at failure also increases first and then decreases with increasing minor principal stress.The performed analysis revealed that the established damage constitutive model effectively considers the influence of minor principal stress and temperature on the strength and deformation of frozen silty clay under complex stresses.
soil mechanicsfrozen silty claymechanical propertiesplane strainstrength criteriondamage constitutive model
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