Evaluation of undrained response from drained triaxial shear tests: DEM simulations and experiments

The undrained shear response of monotonically loaded iso-tropically consolidated saturated sands can be characterised by a change in the excess pore pressure generation in the sample. The generation of positive and negative excess pore water pressures is related to contractive and dilative responses. The increase or decrease in pore water pressure continues until it reaches critical state (known as steady state for undrained tests). In general, Casagrande's definition of critical state for sands has been utilised in most commonly used liquefaction analyses, and is referred to as the steady-state procedure (Castro, 1969; Casagrande, 1977; Castro & Poulos,...