'Sensitivity ratio' and 'sampling disturbance' of natural soils in terms of degradation of soil structure

摘要

"Sensitivity ratio" and "sampling disturbance" of saturated clayey soils are numerically simulated using super-subloading surface Cam-clay model. This elasto-jplastic constitutive model describes the degradation processes both from an overconsolidated state to a normally consolidated state and from a structured state to a destructured state retaining the essentials of the original Cam-clay. The computational results show a clear drop both in preconsolidation pressure and in the undrained shear strength due to the degradation of structure that should occura s plastic shear deformation proceeds during sampling procedure. The higher the degree of initial structure, the higher the sensitivity. Both a preconsolidation pressure drop and a shear strength reduction can be quantitatively estimated to the degree of loss of soil structure due to sampling disturbance.