Longwall roof control through a fundamental understanding of shield–strata interaction

Real-time and non-real-time software has been developed that encapsulates a fundamental understanding of the interaction between a longwall powered support (shield) and the surrounding strata based on the interpretation of the leg pressure data within each load cycle. A load cycle is the change in support pressure with time from setting the shield against the roof to the next release and movement of the support. It is now possible to automatically identify when a shield has too low a set pressure, and when a shield is faulty and/or has an inadequate capacity for the conditions. The use of this software has the potential to significantly reduce or even eliminate roof control problems on a longwall face with significant benefits to both productivity and safety. By automatically identifying potential causes of roof control problems and offering solutions, the software has the potential to aid longwall automation. A Beta test version of the real-time software has been successfully working at BMA's Broadmeadow Mine in Australia for some time and several Australian mines have benefited from expert off-line analyses using the software. The software can also be used to isolate the many interconnected factors affecting roof control on a longwall face, which will enable their quantification, and is therefore a powerful research tool.