Austar Coal Mine (formerly Southlands and Ellalong Collieries)has had a long association with difficult strata control conditionsassociated with mining depth and a highly jointed/cleated coalseam. The conditions include poor longwall face conditions, cyclicloading, heavy tailgate (TG) roadway conditions, and difficultiesin maintaining stable roadways on development at 5.2 m (17ft), as well as the geotechnical challenges of an 8.5-m (27.9 ft)-wide roadway required for installation faces. The introductionof Longwall Top Coal Caving (LTCC) to this environment hasaided in the management of some of these issues, but LTCC hasalso given rise to other geotechnical considerations. Additionalgeotechnical issues associated with LTCC not only requiremanagement during operations, but also require considerationwhen evaluating new mining areas at Austar Coal Mine or potentialLTCC extractable resources throughout Australia and the world.In September 2006, LTCC commenced at Austar Coal Minein longwall panel A1. Since this point the LTCC face has beenincreased from 147 to 216 m (482 to 709 ft)and finally to 227 m(745 ft) in width, and it has also been rehanded and modified inthe three fully extracted panels to date. The application of LTCCin panels A1, A2, A3, and now A4 has been very successful, bothfrom a coal resource recovery point of view and in the managementof the principal hazards of spontaneous combustion and stratacontrol. This paper focuses on the geotechnical aspects of theapplication of LTCC at Austar Coal Mine and also reviews someadvances in general strata control management at the mine.
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