Coal rib response during bench mining: A case study

In 2016,room-and-pillar mining provided nearly 40％ of underground coal production in the United States.Over the past decade,rib falls have resulted in 12 fatalities,representing 28％ of the ground fall fatalities in U.S.underground coal mines.Nine of these 12 fatalities (75％) have occurred in room-and-pillar mines.The objective of this research is to study the geomechanics of bench room-and-pillar mining and the associated response of high pillar ribs at overburden depths greater than 300 m.This paper provides a definition of the bench technique,the pillar response due to loading,observational data for a case history,a calibrated numerical model of the observed rib response,and application of this calibrated model to a second site.