Energy Dissipation and Pore Pressure Generation in Stress- and Strain-Controlled Cyclic Triaxial Tests

The pore pressures generated in soils subjected to cyclic loadings have been shown to be proportional to the energy dissipated in the soil during that loading. Both stress-controlled and strain-controlled cyclic triaxial tests can be used to develop parameters for energy-based pore pressure models; however, the patterns of their energy dissipation into the soil are quite different. In this study, the two patterns of energy-dissipation associated with stress-controlled and strain-controlled cyclic triaxial tests were developed and then confirmed using sixteen stress-controlled and sixteen strain-controlled cyclic triaxial tests. Additionally, it was shown that the patterns of pore-pressure generation for the two tests, which differ greatly when evaluated relative to the cycles of loading, were very similar when evaluated in terms of their energy dissipation.