Hydro-mechanical constitutive model for unsaturated compacted bentonite-sand mixture (BSM): Laboratory tests, parameter calibrations, modifications, and applications

► HM parameters for compacted bentonite-sand mixture (BSM) specimens were calibrated. ► Existing constitutive models were selected and compared to the laboratory test. ► Some features of these models were different from the laboratory test of the BSM. ► Functions to improve the capability of models were proposed. ► Finite element models simulating water infiltration of the BSM were presented.