A numerical evaluation of continuous backfilling in cemented paste backfilled stope through an application of wick drains

Abstract

Cemented paste backfill (CPB) is gaining popularity in many underground mines worldwide. Sufficient water is added into CPB to make a flowable material for pipe transportation. Barricades are built near the drawpoints to prevent in-rush of the fill slurry. To avoid barricade failures resulting from excessive backfill pressures, backfilling is typically performed with a plug pour followed by a final pour. The interval between the two pours should be shortened or removed to increase mining productivity and avoid pipe clogging. Recently, Li proposed to apply wick drains in backfilled stopes to promote drainage and consolidation. The preliminary simulations by considering an instantaneous filling indicated that the drainage of CPB can be significantly accelerated by using wick drains. Barricade was not considered. Here, some new numerical modellings are presented with more representative filling sequences, stope geometry, and different draining configurations. The results illustrate that the stope can be backfilled continuously by using wick drains.