Experimental Study on the Liquefaction Criterion of Saturated Loess

Based on the result of saturated loess in dynamic triaxial test the 3%axial strain is put forward as the key parameter of the liquefaction criterion.The tests show:for the consolidated-undrained tests(CU)of the undisturbed loess, with increasing of the cycles,the structural bonding strength fades away and the volume shrinkage,which transforms into increasing of the pore pressure and decreasing of the effective stress.At last,theinitial liquefactionandcyclic activity phenomena may occur.Normally,3%axial strain occurs before theinitial liquefactionphenomenon and after that,strain increases obviously and pore pressure may reach the initial effective consolidation pressure.Sometimes the sample may be destroyed before theinitial liquefaction.3%axial strain is the critical point between being steady-state deformation and being large deformation.