Modelling of outbursts at #26 Colliery, Glace Bay, Nova Scotia. Part 1: Outburst history and field data

The outbursts experienced at #26 Colliery, Glace Bay, Nova Scotia originated from within sandstone river channels just above, and sometimes penetrating, the coal seam. These outbursts caused delays in driving the main headings, a considerable loss of revenue and threatened the closure of some areas of the mine. A major mine fire has since closed this mine; however, other mines in the Sydney coal field are expected to experience similar problems.

Part 1 of this paper summarises the geology of the Sydney Coal Basin and the geology associated with the outbursts. A brief description of the 37 recorded outbursts is presented. Little data is available to classify the conditions at the outbursts sites but that available, on the rock properties, gas pressures and field stress conditions, is summarised here.

A better understanding of the mechanisms of these outbursts could pave the way to creating a safer and more profitable operation at neighbouring mines. Part 2 of this paper proposes a mechanism that explains these occurrences and a model is developed to analyse the influencing parameters. Part 3 compares the results of the model studies with field observations.