A new concept of backfill design—Application of wick drains in backfilled stopes

Backfilling represents an environmentally friendly mining waste disposal technique. It is increasingly used in underground mines all over the world. However, its primary purpose remains to improve ground stability and to reduce ore dilution. Previous investigations have shown that fill drainage plays a key role in backfill and barricade design. With a poor drainage system in the backfilled stope, the required dimension of barricade, which is constructed at the base of the stope near the drift entrance, has to be increased. A poor backfill drainage system can also lead to a significant increase in drainage waiting time and further reduction in mining productivity. In this paper, the drainage of conventional backfill design in backfilled stopes is briefly reviewed. For the first time, the application of the wick drain is introduced in the backfill within mine stopes. The drainage improvement from the introduction of the wick drain is illustrated using numerical modeling.