Mr. Vandergrift adds over 20 years experience in mining and geotechnical engineering related to ground control, with emphasis on underground mine design and highwall mine design. Tom provides practical ground control solutions for highwall and longwall mining, and mobile roof support retreat operations. His experience includes design of longwall gateroad pillars, pillar retreat cut plans for both partial and full extraction, stress analysis and mine design in multiple-seam environments, subsidence prediction, design of roof support systems, rock and soil mass characterization, in situ stress measurement, instrumentation, and application of seismic imaging techniques to characterize slopes and foundations. Tom routinely uses numerical modeling techniques to aid in developing geotechnical solutions. He developed a suite of design approaches for highwall mine ground control plans that are currently applied throughout the western United States. Tom is a registered professional engineer in Colorado.