VNIPIpromtekhnologii JSC, Moscow, Russia:

A. M. Ioffe, Head of Laboratory, Candidate of Engineering Sciences
D. V. Velichko, Leading Engineer, Velichko.D.V@vnipipt.ru
A. V. Seleznev, Head of Mining Research Department, Candidate of Engineering Sciences
E. S. Mironova, Leading Engineer

Design choices on a technology of mining should be validated in terms of geomechanical safety. Evaluation of the stress–strain curve of rock mass in PIMCU’s Mine 6 was aimed to determine stability parameters of stoping in the Streltsovo Ore Field. The studies involved estimation of rock mass jointing using geological data, and quantitative and qualitative characteristics of rock mass were determined. The stress–strain curve evaluation was carried out in conformity with the effective regulatory documents. After that, the zoning of rock mass was carried out using the obtained data and the VNIMI classification. Concurrently, the stress–strain assessment of enclosing rock mass was performed with the simultaneous calibration of a digital model. The numerical modeling helped find the most efficient system of mining and the expected values of critical displacement preceding rock falls in the roof and sidewalls of stopes. The mine support system with cementitious grouted cable bolting was validated, and the feasibility evaluation of selective mining was performed. The modeling results enabled justification of feasible and safe reduction in volume of backfilling to 67 % at the substantial economic benefit in PIMCU’s mines. After research accomplished in 2013, the Guide for Mining Operations in Guarded Zones in PIMCU’s mines was developed. Advanced perimeter reinforcement in stopes increased their stability and decreased rock falls which added to broken ore dilution. For shafts 13K, 20R and 19 RESH, parameters of concrete lining in long spans and at junctions in shafts were validated. The shaft support calculation was implemented using the finite element method-based modeling and a set of geological data.

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