DYNAMIC CYCLIC STRAIN TESTS ON A CLAY

DYNAMIC TRIAXIAL TESTS ARE DESCRIBED IN WHICH ONE HUNDRED SINUSOIDAL STRAIN-CONTROLLED CYCLES WERE APPLIED TO ARTIFICIALLY-PREPARED CLAY SAMPLES. THE SIGNIFICANT EFFECT ON NORMALLY CONSOLIDATED CLAYS WAS TO REDUCE THE MEAN EFFECTIVE STRESS AT A RATE DEPENDENT ON THE APPLIED STRAIN AMPLITUDE. PEAK SHEAR STRESS AND DAMPING ENERGY WERE FOUND TO BE RELATED TO THE MEAN EFFECTIVE STRESS. THE STRESS-STRAIN RELATIONSHIP SHOWED A DEGRADATION TO AN 'S'-SHAPED LOOP. THE CHANGES IN 'ELASTIC AND PLASTIC PROPERTIES OF THE CLAY ARE ATTRIBUTED TO THE DEVELOPMENT OF A MORE DISPERSED STRUCTURE. /A/RRL/