Dynamic And Static Characteristics Of Saturated Clay Under Complex Initial Stress

The consolidation state imposes great influences on the clay responses to subsequent cyclic loadings.So far most laboratory cyclic tests on clays focused on the isotropically or K₀consolidated conditions,while few considered the anisotropically overconsolidated clays under various ratios of radial to vertical consolidation stresses.In this paper,a series of triaxial shear and long-term cyclic tests are performed on a remolded saturated clay in a triaxial apparatus,where the effects of cyclic stress ratio?CSR?,ratio of radial to vertical consolidation stresses?K?and overconsolidation ratio?OCR?on the deformation behavior are investigated.In addition,a series of consolidation creep tests were carried out under remolded saturated clay,and the effects of consolidation axial stress?P?and overconsolidation ratio?OCR?on the creep characteristics were studied,we try to find some common points between one-dimensional consolidation test and three-dimensional cyclic test under complex initial stress consolidation.The main research contents are as follows:?1?In consolidation creep test,OCR and P have certain influence on the creep characteristics.?2?OCR and K are influence on the deformation characteristics of anisotropically overconsolidated clay under one-way cycle test,and the test results are very different by two CSR definitions.?3?Based on the shake-down theory,in the case of CSR defined by confining pressure,K has no effect on the allowable cyclic stress ratio,and the allowable cyclic stress ratio is 0.43.?4?The accumulation of permanent axial strain is predicted by an empirical model and the quantitative relationships between the fitting parameters and CSR are determined.The relationships of fitting parameter B versus CSR are divided into two different regions by the allowable cyclic stress ratio,indicating that the prediction model of deformation should consider the shake-down ranges.