9
orientation, overburden, stream beds, joints, clay veins, and
caprock thickness might be leading factors in the cause of
this massive roof collapse. Several of these factors overlap
at or near the collapse area, including heading orientation,
prominent clay veins and a close proximately to a stream
bed. However, it is likely that heading orientation and hori-
zontal stress damage is the primary driver of the failure and
is continuing to cause the slow expansion over time of the
collapse area.
This case study is presented to help better understand
how massive roof collapses could result from lateral strata
movement. Lessons learned from the Subtropolis Mine
could provide the underground stone mining industry a
unique insight into how massive roof collapses develop,
which will assist with recognition in similar environments
to improve the health and safety of underground miners.
LIMITATIONS
This study was conducted at one case study site and is not
intended to be applied to all mines with or concerned with
massive ground collapses. Rather, lessons learned from this
case study, the tools used to understand the mechanisms of
failure, and the engineering controls implemented by the
mine to prevent further instabilities are presented to aid
other underground limestone operations in developing a
better understanding of massive ground collapses and the
role geologic conditions and mine design may have in the
cause and prevention of these hazardous events.
Limitations also apply to the Indicators of Potential
Ground Failure Map in Figure 13. Researchers gave the
same weight for all parameters. However, some param-
eters could be more substantial than others and still other
parameters could not be represented at all.
This is a qualitative analysis, and the relative impor-
tance of each parameter is outside the scope of this study.
DISCLAIMER
The findings and conclusions in this report are those of
the author(s) and do not necessarily represent the official
position of the National Institute for Occupational Safety
and Health, Centers for Disease Control and Prevention.
Mention of any company or product does not constitute
endorsement by NIOSH.
REFERENCES
Evanek, N. Iannacchione, A.T. Miller, T. Controlling
Crosscut Damage in Response to Excessive Levels
of Horizontal Stress: Case Study at the Subtropolis
Mine, Petersburg, OH. 2020. Mining, Metallurgy &
Exploration Journal.
Evanek, N., Iannacchione, A., Anderson, T. 2022. A
Case Study of Potential Geologic Factors Affecting
the Occurrence of Massive Strata Collapses in an
Underground Limestone Mine in Southwestern
Pennsylvania. 41st International Conference on
Ground Control in Mining, Canonsburg, PA, July
26–28, 2022.
Iannacchione, A. T. Dolinar, D. R. Prosser, L. J. Marshall,
T. E. Oyler, D. C. Compton, C. S. 1998. Controlling
Roof Beam Failures From High Horizontal Stresses
In Underground Stone Mines. Proceedings of the
17th International Conference on Ground Control
in Mining, August 4–6, 1998, Morgantown, West
Virginia. Peng SS, Holland CT, eds., Morgantown,
WV: West Virginia University, 1998 Aug :102–112.
Iannacchione, A.T. Marshall, Thomas E. Prosser,
Leonard J. 2001. Failure Characteristics of Roof Falls
at An Underground Stone Mine In Southwestern
Pennsylvania. Proceedings of the 20th International
Conference on Ground Control in Mining, August
7–9, 2001, Morgantown, West Virginia. Peng SS,
Mark C, Khair AW, eds., Morgantown, WV: West
Virginia University, 2001 Aug :119–125.
Iannacchione, A.T., Esterhuizen, G.S. and Bajpayee, T.S.,
Swanson, P.L., Chapman, M.C. 2005. Characteristics
of Mining-Induced Seismicity Associated with Roof
Falls and Roof Caving Events. Proceedings of the 40th
U.S. Rock Mechanics Symposium, Anchorage, AK,
June 25–29, 2005. Alexandria, VA: American Rock
Mechanics Association, 2005 Jun :1–10.
Iannacchione, A. Miller, T. Esterhuizen, G. Slaker, B.
Murphy, M. Cope, N. Thayer, S. 2019. Evaluation of
stress control layout at the Subtropolis Mine, Petersburg,
OH. Proceedings of the 38th International Conference
on Ground Control in Mining, Society of Mining,
Metallurgy, and Exploration, Morgantown, WV.
Murphy, M. Ellenberger, J. Esterhuizen, G. Miller, T.
2016. Analysis of roof and pillar failure associated with
weak floor at a limestone mine. International Journal
of Mining Science and Technology.
Newman, D. 2019. The Effect and Measurement of
Horizontal Stress in an Underground Limestone Mine.
Proceedings of the 38th International Conference on
Ground Control in Mining.
orientation, overburden, stream beds, joints, clay veins, and
caprock thickness might be leading factors in the cause of
this massive roof collapse. Several of these factors overlap
at or near the collapse area, including heading orientation,
prominent clay veins and a close proximately to a stream
bed. However, it is likely that heading orientation and hori-
zontal stress damage is the primary driver of the failure and
is continuing to cause the slow expansion over time of the
collapse area.
This case study is presented to help better understand
how massive roof collapses could result from lateral strata
movement. Lessons learned from the Subtropolis Mine
could provide the underground stone mining industry a
unique insight into how massive roof collapses develop,
which will assist with recognition in similar environments
to improve the health and safety of underground miners.
LIMITATIONS
This study was conducted at one case study site and is not
intended to be applied to all mines with or concerned with
massive ground collapses. Rather, lessons learned from this
case study, the tools used to understand the mechanisms of
failure, and the engineering controls implemented by the
mine to prevent further instabilities are presented to aid
other underground limestone operations in developing a
better understanding of massive ground collapses and the
role geologic conditions and mine design may have in the
cause and prevention of these hazardous events.
Limitations also apply to the Indicators of Potential
Ground Failure Map in Figure 13. Researchers gave the
same weight for all parameters. However, some param-
eters could be more substantial than others and still other
parameters could not be represented at all.
This is a qualitative analysis, and the relative impor-
tance of each parameter is outside the scope of this study.
DISCLAIMER
The findings and conclusions in this report are those of
the author(s) and do not necessarily represent the official
position of the National Institute for Occupational Safety
and Health, Centers for Disease Control and Prevention.
Mention of any company or product does not constitute
endorsement by NIOSH.
REFERENCES
Evanek, N. Iannacchione, A.T. Miller, T. Controlling
Crosscut Damage in Response to Excessive Levels
of Horizontal Stress: Case Study at the Subtropolis
Mine, Petersburg, OH. 2020. Mining, Metallurgy &
Exploration Journal.
Evanek, N., Iannacchione, A., Anderson, T. 2022. A
Case Study of Potential Geologic Factors Affecting
the Occurrence of Massive Strata Collapses in an
Underground Limestone Mine in Southwestern
Pennsylvania. 41st International Conference on
Ground Control in Mining, Canonsburg, PA, July
26–28, 2022.
Iannacchione, A. T. Dolinar, D. R. Prosser, L. J. Marshall,
T. E. Oyler, D. C. Compton, C. S. 1998. Controlling
Roof Beam Failures From High Horizontal Stresses
In Underground Stone Mines. Proceedings of the
17th International Conference on Ground Control
in Mining, August 4–6, 1998, Morgantown, West
Virginia. Peng SS, Holland CT, eds., Morgantown,
WV: West Virginia University, 1998 Aug :102–112.
Iannacchione, A.T. Marshall, Thomas E. Prosser,
Leonard J. 2001. Failure Characteristics of Roof Falls
at An Underground Stone Mine In Southwestern
Pennsylvania. Proceedings of the 20th International
Conference on Ground Control in Mining, August
7–9, 2001, Morgantown, West Virginia. Peng SS,
Mark C, Khair AW, eds., Morgantown, WV: West
Virginia University, 2001 Aug :119–125.
Iannacchione, A.T., Esterhuizen, G.S. and Bajpayee, T.S.,
Swanson, P.L., Chapman, M.C. 2005. Characteristics
of Mining-Induced Seismicity Associated with Roof
Falls and Roof Caving Events. Proceedings of the 40th
U.S. Rock Mechanics Symposium, Anchorage, AK,
June 25–29, 2005. Alexandria, VA: American Rock
Mechanics Association, 2005 Jun :1–10.
Iannacchione, A. Miller, T. Esterhuizen, G. Slaker, B.
Murphy, M. Cope, N. Thayer, S. 2019. Evaluation of
stress control layout at the Subtropolis Mine, Petersburg,
OH. Proceedings of the 38th International Conference
on Ground Control in Mining, Society of Mining,
Metallurgy, and Exploration, Morgantown, WV.
Murphy, M. Ellenberger, J. Esterhuizen, G. Miller, T.
2016. Analysis of roof and pillar failure associated with
weak floor at a limestone mine. International Journal
of Mining Science and Technology.
Newman, D. 2019. The Effect and Measurement of
Horizontal Stress in an Underground Limestone Mine.
Proceedings of the 38th International Conference on
Ground Control in Mining.