Developments in coal pillar design at Smoky River Coal Limited, Alberta, Canada

ABSTRACT

Smoky River Coal Limited (SRCL) mines low volatile metallurgical coal by surface and underground methods in the foothills of the Rocky Mountains of Alberta. Current underground operations are confined to the 5B-4 Mine. Development of 5B-4 began in January of 1998, and production from de-pillaring sections commenced in July of the same year.

This paper briefly describes the history of underground mining on the Smoky River property in terms of extraction methods and pillar design. The development of the present pillar design guidelines is discussed in this context.

Recent work to prepare a number of case histories for back analysis using the ARMPS method is described, along with the modifications developed for calculating the ARMPS stability factor for retreat extraction of thick seams. The design criteria developed is described, as well as brief details of the geotechnical program implemented in order to verify its applicability.