In 2020, a confidential power client called upon Barr’s coal mining experience and geotechnical services to better understand the feasibility of a proposed 100 MW solar power project in the Appalachian Mountains. The proposed 1400-acre site was previously used as surface mining for mountaintop coal reserves and has since been graded and reclaimed. Barr’s mining and geotechnical team completed a desktop-based analysis of potential for future settlement, future underground mining, differential movement, and related risks to provide a better understanding of the past mining activities’ implications for siting and design.
To complete the analysis, Barr’s team first had to review site-specific information to identify the previous mining methods and associated depths, as well as locations of key mountaintop coal mining features such as valley fills, areas with surplus mine spoil locations, and impoundments. Barr’s mining engineers collaborated with GIS specialists to develop a means of calculating mine spoil thickness. Using LiDAR and InSAR data, our team then completed a settlement analysis of potential spoil movements and differential settlement.
In addition to the articulated potential risk associated with mine subsidence and anticipated strain resulting from differential settlement, Barr’s deliverable also provided recommendations on setbacks and layout and design concepts. Using this information to proceed with a more detailed design of the solar power project, Barr’s client appreciated our valuable insight based on our mining expertise.