Effect of Initial Consolidation Condition on Postcyclic Undrained Monotonic Shear Behavior of Mississippi River Valley Silt

Abstract

AbstractThe postcyclic undrained monotonic shear behavior of Mississippi River Valley (MRV) silt is investigated by carrying out triaxial tests under various initial consolidation conditions. Results show that the variation of cyclic shear strength of MRV silt against initial overconsolidation ratio (OCR) and mean effective consolidation pressure (σc′) was consistent with previous studies, i.e., it increased with both increase in OCR and decrease in σc′. The cyclic stress ratio (CSR) had no apparent effect on postcyclic shear behavior for MRV silt. At higher OCRs, the postcyclic reconsolidation behavior was more similar to recompression. Unlike the specimens not previously subjected to cyclic loading, the initial OCR did not influence effective stress path of the postcyclic reconsolidated specimens at the early stages of shearing. The normalized undrained shear strength (Su,OC/Su,NC) of MRV silt reconsolidated after cyclic loading increased with OCR. Stress-strain curves of MRV silt reconsolidated after c...