Hyperbolic Hydro-mechanical Model for Seismic Compression Prediction of Unsaturated Soils in the Funicular Regime

A semi-empirical elasto-plastic constitutive model with a hyperbolic stress-strain curve was developed the goal of predicting seismic compression unsaturated sands in funicular regime soil-water retention (SWRC) during undrained cyclic shearing. Using flow rule derived from energy considerations, evolution plastic volumetric strain (seismic compression) predicted shear strains hysteretic curve. The are used to predict changes degree saturation phase relationships and pore air pressure Boyle’s Henry’s laws. estimate matric suction transient scanning paths SWRC. Changes small-strain modulus estimated mean effective stress computed constant total pressure, suction, turn affect curve’s shape strain. calibrated using experimental backbone curves drained simple tests SWRC path measurements tests. Then predictions were validated data on sand specimens different initial degrees regime. While captured coupled hydro-mechanical variables (pore water saturation, strain, stress, modulus) well over first 15 cycles shearing, less accurate after continued shearing up 200 cycles. After large numbers linear decreasing trend between while nonlinear increasing-decreasing observed experiments. This discrepancy may be due not considering post reconsolidation model, calibration parameters, or issues including drift position shear-stress Nonetheless, is consistent previously- empirical models developments new mechanistic this study will play key role future development holistic for across all regimes