Coal Rib Geomechanics: A Numerical Approach for the Analysis of Rib Stability in Underground Coal Mines


Coal rib stability is the benchmark for pillar reliability studies. Standard rib control procedures are still lacking in most countries. Current rib control practices are based on a ninety-degree rotation of roof control techniques. This is guaranteed to cause rib stability problems since the structural layout of the geological units such as beddings planes, cleats, partings etc., in the roof and rib with respect to the excavation face are different. There is insufficient knowledge and understanding of the geomechanical behavior of ribs. In light of this dearth in knowledge, this research aims to contribute to the understanding of rib behavior by adapting the distinct element modeling (DEM) of the deformation and loading behaviors of coal ribs. DEM is chosen because of its superior advantage to explicitly represent both discontinuities and their constitutive behaviors, besides that of intact rock matrix. To analyze the rib stability, a numerical monitoring protocol is implemented to monitor the deformation characteristics of the pillar rock mass as its strength is gradually reduced and the displacement and safety factors are established. Additionally, a criterion is implemented to realistically judge the critical failure state of zones in the coal rib. The results demonstrated the capacity of DEM to capture the progressive crack development in the pillar rib. The concept of adapting the limiting strength reduction factor as the factor of safety is however not clearly established in this study.

Meeting Name

54th U.S. Rock Mechanics/Geomechanics Symposium (2020)


Mining Engineering

Document Type

Article - Conference proceedings

Document Version


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Publication Date

01 Jan 2020