Behavior of Unsaturated Clayey Soils at High Strain Rates.

摘要

Specimens of clayey soils with a controlled pore solution chemistry were prepared, consolidated, and equilibrated at three different soil suction levels. Some specimens were subjected to creep/recovery tests in conventional triaxial cells. These results were used to select viscoelastic models that could explain the specimen behavior. Duplicate specimens equilibrated at the same soil suction levels were tested in a dynamic triaxial test system. For this purpose, the specimen was subjected to a series of stress controlled pulses of 50msec duration and consisting of a ramp-up to a peak deviatoric stress and a ramp-down to zero. The peak stress was increased for successive pulses. The response of the specimen, and the strain-time history, was then recorded. The non-linear viscoelastic models fitted to creep-recovery tests were used in combination with the modified superposition principle to predict the expected response of the specimen. The viscoelastic models that were fitted to the steady creep phase did not provide the best match. It was rather necessary to use the models fitted to the initial part of the transient creep phase.... Creep, High strain rates, Unsaturated clayey soils.