Post mining subsidence abatements in Wyoming abandoned coal mines

Abstract

Coal has been mined continuously in Wyoming since 1865. Nearly all the coal produced in the first 90 years of mining was from underground bituminous mines. Subsidence has been a threat in Wyoming since the beginning of coal mining; constituting an extreme danger to public health, safety and property. As a consequence, Wyoming mine subsidence problems qualify for the highest priority of funding under the Surface Mine Control of Reclamation Act of 1977. Abatement projects have been undertaken by the Wyoming Abandoned Mine Lands (AML) Program to prevent or minimize further subsidence in Wyoming communities. This paper gives a brief historical account of mining activity in Wyoming. Subsidence characteristics and occurrences in various communities are presented. The locations of key abatement projects and the reasons for their selection are then given. The selection criterion for the backfilling and grouting methods and the techniques themselves are presented, and the problems encountered during various projects are discussed. Successful projects are analyzed and recommendations for future projects are given.