AMCMRR - an analytical model for coal mine roof reinforcement

An analytical model for coal mine roof reinforcement (AMCMRR) has been developed. AMCMRR utilises a Factor of Safety (FOS) approach which is commonly used in all forms of engineering. The starting point in the development of AMCMRR was an existing analytical roof behaviour and roof support design methodology/model originally developed by the second author. This technique was being successfully utilised in the Australian underground coal industry for roof support evaluation and design prior to and during the course of the ALTS 2006 research project and when used was essentially calibrated on a site by site basis. It has long been recognised that bolts and longer tendons can modify the behavior and load bearing capacity of the reinforced roof via the concept of beam building. The break-through in the development of AMCMRR was combining the original analytical model with the ALTS database to effectively quantify this reinforcing effect and this in turn provides the “platform” by which this analytical model can be calibrated for the entire Australian underground coal industry. The two techniques (analytical-AMCMRR and empirical-ALTS 2009) now work together as a part of an overall and more robust roof support/longwall gateroad design methodology. This paper focuses on the application and use of AMCMRR and the analyses undertaken to quantify the reinforcement offered to the immediate roof via the concept of beam building