Experimental study on strength characteristics of soil-cement under axial symmetry condition

Based on the constant p triaxial shear test,conventional triaxial consolidation-drained shear test(CD) and triaxial consolidation-undrained shear test(CU),the mechanical property of soil-cement is studied;in which the variation characteristics of the stress-strain curve,and the strength characteristics of the soil-cement are discussed.The results indicate that:(a) the stress-strain curve of the soil-cement behaves as strain softening,and the soften rate is related to confining pressure;(b) different stress paths have some but little influences on the strength of the soil-cement;(c) under low confining pressure,the soil-cement has the dilatancy property,and are similar to quasi over consolidation;but under high confining pressure,cement-soil has the dilatancy property,and are similar to slightly over consolidated soil;(d) the residual strength increases linearly with the increase of confining pressure;The residual strength of CD test is greater than that of the CU test;The ratios of residual strength and peak strength increase with the increase of confining pressure,while the increasing rate decreases;the effective stress envelope of CU test and that of CD test are basically identical.