COUPLED THERMO-HYDRO-MECHANICAL-CHEMICAL MODEL FOR OVERPRESSURE EVOLUTION IN ACCRETING MINE FILLS

Cemented mine fills have been extensively used in subsurface mining worldwide for their superior environmental, mechanical and economic benefits. The stability of backfill systems hinges upon the evolution of pore water pressure in response to the coupled thermo-hydro-mechanical-chemical(THMC)effects during mine fill deposition. In this study, a multiphysics framework for cemented mine fills is first developed by extending Biot's classical poroelasticity, and a one-dimensional overpressure model is then derived for the thermo-chemical consolidation of accreting mine fills. The coupled THMC effects on overpressure evolution are demonstrated by scrutinizing the accretion of cemented mine fills under various sedimentation rates and thermal conditions.