Large surface coal mines in Wyoming\u27s Powder River Basin ship millions of tons of coal per annum, moving millions of cubic yards of overburden to mine the coal. Much of this volume is blasted in the form of benches, a common mining technique. Increases in production and scale of equipment in the past thirty-five years have created a paradigm shift for drill and blast personnel at these large surface mines, and the explosives industry has yet to create a blast design method specifically tailored for large surface coal mine bench blasting.
This research examines the typical scale of bench blasting at large surface coal mines, develops a new method of design tailored for these operations, and tests the new method against two widely accepted traditional blast design methods. Novel contributions of the research include a new universal scale of energy distribution known as Available Energy, and an entirely powder factor based blast design method that uses cut width as part of the design process. Numerical comparison testing is done at both small borehole diameters (corresponding to the original domain of the traditional blast design methods) and at large borehole diameters. A comparison of the new method and existing major methods of traditional blast design is monitored graphically, and linear regression is used to track the improvement of the accuracy of the match.
Finally, the new design method is presented in nomograph form to facilitate use in the field. Development of the nomograph is discussed and sample nomographs for specific design conditions are included. Recommendations for future work and broader applications of the Available Energy paradigm are given to conclude the dissertation. --Abstract, page iii
