Elk Creek Geotechnical Program
Agapito Associates, Inc. (AAI) has been involved in long-term geotechnical investigation and design at the Oxbow Mining, LLC, Elk Creek Mine, dating back to the pre-development phase. Services provided by AAI include horizontal stress measurement, numerical modeling of seam interaction, rock mechanics testing, and mine-wide roof and floor characterization. Future mining involves increased cover depth, and one of the primary areas of work is in developing pillar design strategies appropriate for the increased cover. Recently, AAI designed and installed an extensive geotechnical instrumentation system for characterizing ground response to longwall abutment loading, including pillar loading, entry convergence, and roof deflection. The resulting data was used to calibrate numerical modeling inputs to observed ground response. Modeling and other design approaches were then used to develop a range of pillar design strategies for Oxbow in support of mine planning.