ABSTRACT
Violent ejections of coal and gas from the working coal seam have plagued underground mining operations for over a century. These phenomena are referred to as instantaneous outbursts and have occurred in virtually all the major coal producing countries and have been the cause of major disasters in the world mining industry. The coal and gas outbursts range in size from a few tonnes to thousands of tonnes of coal with corresponding gas volumes from tens of cubic metres to hundreds of thousands of cubic metres. In fact, coal and gas outbursts can release over one million cubic feet of gas, fractured and even pulverised coal and rock (Figure 18.1). Thus, the occurrence of coal and gas outbursts in coal mines and caverns has posed great potential threat to facility operators and has challenged researchers from the rock mechanics and rock engineering community. In the last century and a half, since the first reported coal and gas outburst occurred in the Issac Colliery, Loire Coal Field, France, in 1843 (Lama and Bodziony, 1998), it is estimated that as many as 30,000 outbursts have occurred in the world coal mining industry. The majority of outbursts, more than one third of the total, have occurred in China.
