Author ORCID Identifier

Date Available


Year of Publication


Degree Name

Master of Science in Mining Engineering (MSMIE)

Document Type

Master's Thesis




Mining Engineering

First Advisor

Dr. Zach Agioutantis


Underground mining operations utilize the room-and-pillar mining method that extracts the orebody and creates ‘rooms’ and leaves the remaining in-situ material as ‘pillars’ to support the overburden. Room-and-pillar mines are traditionally designed in square or rectangular-shaped pillars. This work presents laboratory experiments testing the compressive strengths of specimens modeled after square and parallelogram-shaped pillars and numerical models of square and -parallelogram-shaped pillar systems. The uniaxial compressive strength of the specimens’ shape and the observations of the extent of the specimen core post-failure were analyzed. There was insufficient evidence from the laboratory experiments to conclude that there is a difference in strength between the specimen shape. The inconclusive evidence is a result of the high variance in strength between the specimens and this could be a result of improper preparation. However, there were observations in individual batches that suggested there is a difference in strength. It was concluded from the numerical modeling that the square pillars could bear a higher load than the parallelogram pillars.

Digital Object Identifier (DOI)

Funding Information

This publication was supported by Central Appalachian Regional Education and Research Center through Grant 6T42OH010278. Its contents are solely the responsibility of the authors and do not necessarily represent the official views of the National Institute for Occupational Safety and Health/Centers for Disease Control and Prevention.