Experimental Inspiration for Kinematic Hardening Soil Models

Traditional techniques for identifying yielding of soils in the context of classical elastic–plastic soil models are criticized. However, the extended use of such procedures starts to reveal the kinematic nature of the plastic behavior of soils. It is suggested that the experimental determination of stress response envelopes can provide an objective route toward the collection of stress–strain behavior for soils. Stress response envelopes are presented for true triaxial tests on clay and sand: these clearly reveal the kinematic nature of the soil behavior. Response envelopes are presented for different magnitudes of strain probes. As the magnitude of a strain probe increases, the kinematic element of the response decays and the memory for the increasingly distant history is swept out.