Engineering & Mining Journal

NOV 2018

Engineering and Mining Journal - Whether the market is copper, gold, nickel, iron ore, lead/zinc, PGM, diamonds or other commodities, E&MJ takes the lead in projecting trends, following development and reporting on the most efficient operating pr

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ROCK BOLTING 62 E&MJ • NOVEMBER 2018 www.e-mj.com Rock mechanics is one of the areas that separates mining engineers from the oth- er disciplines. Understanding the com- pressive strength of rock and the influ- ence of stress and strain, they can safely determine the unsupported span for a development heading. Those ground sup- port decisions are based on several fac- tors including among others depth, ambi- ent conditions and how long that area of the mine will be in use. Ultimately, the geologic formation de- termines the safety factor of that design. As miners pursue deeper orebodies, rock pressures build. More complex mining methods involve active caving, which re- lieves stress if designed properly. These scenarios, however, change from a purely static set of forces in cut-and-fill mining to one that now must consider dynamic forces. Dynamics complicates everything. Sometimes the Earth wins and the best engineering designs fail. These situations obviously increase with depth. When the regular roof support plan encounters a geological anomaly or water, or both, ad- ditional techniques are usually required to safely support the area and get produc- tion back on track. Selecting the Right Rock- bolting Technology One of the company's servicing this aspect of mining, Germany's DSI Under- ground, recently shared some of its expe- riences from different operations around the world. The company's latest litera- ture, DSI Underground Spotlight 1 2018, which is avaiable at: https://www.dsiun- derground.com, would win the award for best coffee table book for rock bolting, if such an award existed. In addition to internal news about plants and products, the piece discusses success story at tunneling jobs and min- ing operations. One item discusses rock bolt selection for the exploration ramp at Goldcorp's Borden mine in Ontario. An- other provides details on the ground sup- port techniques for deep mining at the Cuiabá gold in Brazil and the El Roble mine in Mexico. In the last few years, a great deal of news has been reported about the Gold- corp's Borden mine in Ontario. Much of that reporting covered the mine's decision to operate carbon-free, but before any of that can happen, the orebody has to be accessed. A little less than two years ago, Goldcorp began driving an access ramp. Prior to developing the portal, DSI Under- ground Canada participated in a technical committee to assist in the rapid devel- opment of the mine. DSI engineers pro- posed alternate solutions to the generic methods of ground support. They thought the typical resin and rebar supports used in northern Canada would have prolonged the startup due to limitations from ex- treme temperatures. For this reason, the mine decided to use the DYWI Drill Hollow Bar Bolt. It can be New Developments in Rock Bolting Ground control products and technologies mitigate issues at depth By Steve Fiscor, Editor Miners install a lightweight fiberglass rock bolting system at the El Roble Mine. The system is equipped with GRP anchors with high-tensile load bearing capacity.

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