Backfill optimization using mine tailings for improved ground stability in underground mines.

摘要

Mine backfill has been widely used as a means of ground support. While proper design of backfill is important to ensure ground stability, understanding the failure mechanism and the various influencing factors in a filled block is essential. This research presents a modified sliding failure model of a confined backfill block. The model considers both the gravity of the backfill itself and the overlying load from fragmented ore or backfill on the top. A series of new equations are derived by considering overlying load and the relationships between factors such as: Factor of safety, Friction angle, Cohesion and the Exposed stope height are developed. This modified model will be useful for optimizing design of backfill for a given stope geometry.; Beyond the analytical techniques described above, numerical modeling evaluated to examine mine stability problem. Presently some mines around the world are practicing with placing paste backfill by layers in a stope. Numerical modeling can be used to find the optimum thickness of the backfill layers with the required strength. Each layer has different binder content and different strength. Considering that we can design economically backfilled stopes, numerical modeling is effectively used to study the stress redistribution and ground movement in the backfill and surrounding stopes. A series of numerical modeling were conducted to find out the suitable thickeners of the backfill layers with optimum binder content in the field conditions.