In Situ Seismic Investigations for Evaluating Geotechnical Properties and Liquefaction Potential of Fine Coal Tailings

This paper presents a field seismic investigation that is effective in evaluating the in situ geotechnical properties and liquefaction potential of fine coal tailings subjected to mine blasting. In this study, seismic refraction, multichannel analysis of surface waves, and seismic monitoring are performed on two coal tailings impoundments in Appalachian coalfields in the United States. Shear wave velocity, compressional wave velocity, Poisson's ratio, small-strain Young's modulus and shear modulus, and peak particle velocity of the fine coal tailings are derived. A relatively high rate of vibration attenuation is observed for the fine coal tailings when compared to other blasting applications. The fine coal tailings are evaluated to be potentially liquefiable when subjected to ground vibrations from mine blasting based on the simplified procedure for liquefaction evaluation with slight modifications and the input parameters from the seismic investigations. The nondestructive techniques and methodology described herein can serve as an alternative for liquefaction assessment.