Underground » Coal Burst
Coal burst events are rare in the Australian coal industry. However, their occurrence appears to be increasing in some limited deeper mines. Understanding such phenomena in the Australian industry is primarily qualitative and has previously been based on overseas experience. Although there is anecdotal evidence that coal bursts may have occurred previously in Australian coal mines, research into this phenomenon in Australia has only been systematically initiated by ACARP in 2014.
An ACARP scoping project was completed in April 2016. This continuation project, C25004, was initiated in October 2016. The main objective of C25004 was to develop preliminary coal burst control guidelines for Australian coal mines.
This objective was met by:
1. conducting an international review of coal burst practices,
2. reviewing Australian coal bumps and burst experiences,
3. reviewing international and local established experiences and failure mechanisms,
4. identification of recommended coal burst control technologies,
5. evaluation of control technologies against the Australian experience, regulations, mine design, and operational practices.
It is recognised there is a lack of universally accepted and unique set of definitions for the terms that can be used to refer to dynamic rock failure events (including rockburst, strain burst, bump, etc.). It is hoped that the proposed terminology in this report can be adopted as accepted definitions for use across the Australian coal industry. It is considered imperative that a consistent form of recording of such events is adopted across the Australian coal mining industry.
Analysis of seismic data revealed in chapters 2. that there are no correlations between recorded seismic events using the Geoscience Australia monitoring system and the coal burst that occurred in the mining regions in question. Chapter 3, discussed coal burst management in underground coal mines. The Chinese coal burst experience is reviewed in Chapter 4 where it was concluded that the characteristics of coal burst occurrence are a non-linear dynamic process of steady accumulation and rapid release of elastic strain energy. A total of 133 coal burst events during roadway development at six coal mines were analysed to determine the common characteristics in chapter 6, it summaries three common characteristics of these mines that may be responsible for those burst events. Chapter 7 presents analytical approaches to assess strain energy transition with zero and nonzero gas pressures. Further analysis on coal burst mechanisms relative to gas pressure is presented in Chapter 8. A semi-quantitative coal burst risk classification system, BurstRisk, is presented and discussed in Chapter 9. A proposed coal burst management framework has been developed and discussed in Chapter 10. This framework includes three stages, namely identification of risk, development of a management plan, and management of coal burst. Chapter 11 closes this body of works out by presenting a summary of the focused workshop on international coal burst experience and research direction including a coal burst risk assessment to improve the level of understanding of this potentially hazardous phenomenon.
The scoping project report which was completed in April 2016 and this continuation project report are both available as a combined report.