SOMA
A New Technique to Reduce Roof Falls and Improve Safety and Profitability in Coal Mines
Byington, C.B., 2004, SOMA: A new method to calculate the operative stress field: Results from the Laurel Mountain Mine, Russell Co., Virginia: in proceedings of 23rd International Conference on Ground Control in Mining, Peng, S.S., Mark, C., Khair, A.W., and Heasley, K., eds., pp. 103-111.
The SOMA (Stress-field Orientation Mapping and Analysis) technique is a new way to understand roof falls in coal mines and reduce the likelihood of their occurrence. It focuses on calculating the operative stress-field orientation, and defining its interaction with natural weakness planes in the adjacent rock mass. These weakness planes, when opened by the stress field as fractures, result in the loss of cohesion and encourage roof, rib and floor failures. Before the SOMA technique was developed it was not possible to define which of the potential weakness planes would become open fractures associated with roof falls.
Fractures surrounding the mine excavations, either naturally occurring or mining induced, are uniquely necessary for every roof fall in every mine regardless of all other factors. The text explains the step-by-step procedure for collecting, organizing and statistically treating mine fracture measurements, and determining the optimal orientation for the mine workings and the optimal roof-bolt pattern. The solution statistically prioritizes the fractures that are most likely to be opened because of their orientation to the operative stress field. The SOMA technique describes a solution that benefits the miner’s safety and profitability by working with the rock mass rather than by spending money, time and manpower to fight the natural tendencies of the rock. Two-dimensional finite-element modeling is used to illustrate the importance of employing fracture analysis in any roof control solution including those addressing roof-bolt types and patterns.
*** Please note you will need Adobe's Acrobat Reader or Microsoft Word Viewer in order to view documents on this page.
Contact Us Freedom of Information Act Web Policy WAI Level A Compliant