Numerical Analysis of the Hydraulic and Mechanical Behavior of In Situ Cemented Paste Backfill

Although the most explicit approach to acknowledge the behavior of in-stope CPB is to utilize monitoring instruments to collect relevant data, such as pore water pressure, total stress and temperature, the in situ monitoring may lead to production delays and rising costs. An alternative solution is using numerical simulation method to understand the behaviors of field CPBs that are placed in stopes. Hence, a numerical model, which considers the binder hydration process, hydraulic (pore water pressure) and mechanical (total stress, uniaxial compressive stress) properties, is developed to analyze the performances of in-stope CPBs. The proposed model is validated by comparing field monitoring data with corresponding results predicted by model simulation. Satisfactory agreement is detected between the modeling results and monitoring data, validating the capability of the developed model in well describing the hydraulic and mechanical behaviors of CPBs placed in field stopes. Understanding the characteristics of field paste backfill matrix is of great importance in improving its ultimate mix design with respect to cost savings. This study also contributes to a better understanding of the hydro-mechanical performance of field CPB structures.