Design and control of large hydraulic backfill pours

CIM Bulletin, Vol. 75, No. 838, 1982

JOHN D. SMITH, John D. Smith Engineering Associates Ltd. Kingston, Ontario, ROBERT J. MITCHELL, Professor of Civil Engineering, Queen's University, Kingston, Ontario

There is a world-wide trend toward underground bulk mining methods employing hydraulically placed backfill. This trend is recent and therefore there is little in the literature to assist an operator in the design of backfill properties, the design of drainage facilities, the calculation of the operating forces on a bulkhead, and the control procedures considered necessary before, during and after pouring. This paper presents recommended procedures that are based on over 10 years of experience in the various aspects of backfilling large openings. Free-draining timber or concrete block bulkheads are shown to be a viable alternative to massive reinforced concrete bulkheads for the containment of backfill pours. Hydrostatic pressures cannot develop in backfills provided adquate drainage facilities are installed.
Keywords: Underground mining, Backfilling, Hydraulic backfill, Bulkheads, Drainage, Plugs, Cemented tailings.