Coarse Tailings Sand Densification By Dozer Packing

ABSTRACT: Upstream construction tailings dams in the oil sands mining industry rely on a compacted shell and beaches of non-liquefiable sand to contain the pond and internal loose beach deposits. Compaction energy to densify the sand in the shell is provided by dozers which densify the sand through the vibration of trafficking repeatedly across the sand surface, together with the downward drainage of construction water through the sand. This paper updates previous published data on dozer track-packing effectiveness, based on operational experience and addresses the influences of: dozer size, tailings sand gradation, and sand moisture content. Observations on equipment productivity are given in terms of cubic metres of densified sand per operating hour. The effectiveness of the densification was assessed using cone penetration testing, surveys of the surface settlement, and visual observations of water liberated from the beach.