Multiphysics Model for Consolidation Behavior of Cemented Paste Backfill

Abstract

In underground mining practices, cemented paste backfill (CPB), a mixture of tailings, cement, and water, is widely adopted to fill extracted stopes. During and after the filling of the underground mine excavations or stopes with CPB, complex multiphysics processes (including thermal, hydraulic, mechanical, and chemical) take place in the CPB mass. These multiphysics processes and their coupling govern the consolidation characteristics and behavior of CPB. As a result, conventional soil mechanics consolidation theories and models are not appropriate for the evaluation and prediction of the consolidation behavior of CPB. Therefore, based on the principles of the continuity of pore space and conservation of mass, energy, and momentum, a three-dimensional coupled multiphysics consolidation model for CPB was developed in this study. The prediction capability of the proposed model was verified by comparing the predicted results with experimental data. Good agreement between the predicted values and experimental data was obtained. Furthermore, some of the important features of the developed model are highlighted by a comparison between the simulated results and Gibson’s solution.