Abstract
In order to investigate an effect of stress history on K0 value and a change in undrained shear strength which caused by secondary consolidation during K0 condition, triaxial compression tests using undisturbed marine clay were carried out by using an automatic control equipment. Results from laboratory K0 consolidated undrained shear test could be summarized as, 1) K0 value would be strongly affected by clay structure which depend on ageing effects chemical cementation and be subject to stress history. 2) K0 value would be kept constant during secondary consolidation. 3) A unique effective stress path was showed due to the effect of dilatancy properties and softening stress-strain relationship during secondary consolidation. 4) qmax and E50 would be increasing in proportional to consolidated elapsed time on scale of logarithm before reaching to C. S. L line, and they would be independent of the time after reaching the C. S. L line. 5) qmax was located in an inherence line in p′-q plane. 6) It is possible that qmax could be estimated by a simple function based on the test results.
