STATE PRESSURE INDEX FOR MODELING SAND BEHAVIOR

Efforts to model sand behavior within a critical-state soil mechanics framework would benefit from a state variable relating the current void ratio and mean pressure of the soil to its void ratio and mean pressure at the critical state. In this paper, the authors propose a state pressure index, I-sub-p, which is defined as the ratio of the current mean pressure to the mean pressure at the critical state corresponding to the current void ratio. Using this state pressure index, a bounding surface hypoplasticity model for sand is modified so that the phase transformation and failure stress ratios both depend on I-sub-p and merge into the critical-state stress ratio at failure. The I-sub-p dependency introduced enables use of a single set of model constants in modeling sand behavior for various initial confining pressures and densities under undrained/drained conditions. Dilatancy and strain softening and hardening are simulated for loose and dense sands. Simulations from the modified model are compared to results of lab tests of drained/undrained triaxial compression.

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  • English

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  • Accession Number: 00925084
  • Record Type: Publication
  • Files: TRIS
  • Created Date: May 30 2002 12:00AM