ICGCM Papers:
Pillar Design Workshop
 
 
An Evaluation of Time to Failure of Coal Pillars in Australia
Pillar Mechanics Workshop Proceedings 2010
An Evaluation of Time to Failure of Coal Pillars in Australia
by
fiogf49gjkf0d
Ismet Canbulat, Principal Geotechnical Engineer Anglo American Metallurgical Coal Brisbane, Australia
Download PDF Add to My Library
[Book] Pillar Mechanics Workshop Proceedings 2010
[Topical Area] Pillar Design Workshop
[Author] 
fiogf49gjkf0d
Ismet Canbulat, Principal Geotechnical Engineer Anglo American Metallurgical Coal Brisbane, Australia
[Abstract] 
fiogf49gjkf0d
Following the Coalbrook Colliery disaster in 1960, Salamon and Munro (1967) established the well know empirical coal pillar strength formula in South Africa. This formula has prevented further violent multiple pillar failures. In 1996, a back analysis of the collapsed and uncollapsed cases in Australia led to the development of the Australian empirical coal pillar strength formulae. The original collapsed and uncollapsed coal pillar database of Salamon and Munro (1967) was updated in 2006. This study introduced strength formulae for different coalfields and seams in South Africa through back analyses of collapsed and uncollapsed cases. Today, the resultant pillar strength formulae from these previous studies and the behaviour of the coal pillars are mostly well understood and applied with confidence. However, it was assumed in the previous studies that the behaviour of pillars is not time dependent; therefore, the formulae established do not provide an associated time to failure of coal pillars. This paper attempts to evaluate the so called “Geometrical Limits” concept to provide the Australian coal mining industry with a tool to assess the long-term behaviour of bord and pillar workings where the pillars are prone to failure due to spalling of ribs. In order to achieve this outcome, the principles of safety factor and the probability of failure calculated using the coal pillar strength formulae have also been evaluated and the results are presented in this paper.