Ground Support at Craigmont

CIM Bulletin, 1968

A. J. PETRINA, Mine Manager, Craigmont Mines Limited, Merritt, B.C.

At Craigmont Mines Limited, Merritt, B.C., tests were begun in March, 1965 to evaluate the use of shotcrete as a method of ground support m development headings; previously, all drifts had required support, wh1ch was accomplished mainly by timber and occasionally by the use of rockbolts. The tests demonstrated conclusively the effectiveness of shotcrete for supporting Craigmont's ground. Gradually, the use of timber for ground support was virtually eliminated in favour of shotcrete. This paper describes the equipment used, the operation of the equipment, pertinent cast data and opera ting details. Also discussed are other uses developed for the shotcreting equipment, the use of reinforcing bar rockbolts, and a method used at Craigmont for lining long vertical ore passes with steel plate and concrete as part of the raising cycle.
Keywords: blasting, calcium chloride, concrete, Craigmont, reinforcing bar, shotcrete, Concrete, Drifts, Equipment, Raises, Sand, shotcrete, Support, Supports