Rock and gas outbursts - laboratory tests and in-shaft measurements

Authors: J. Topolnicki, M. Wierzbicki, N. Skoczylas

The paper briefly reviews the main areas of research work on gas and rock outbursts. Tests were conducted in laboratory conditions and in situ.

In the laboratory at the Strata Mechanics Research Institute the model was developed reproducing the initiation of a gas and rock outburst, the process involved being the gas filtration.

Measurements of gas pressure ahead of the longwall face in the colliery "Pniówek" were taken to ensure that the model well captures the natural conditions.

The results suggest ahead of the face region there is a high pressure zone, known as the degassing barrier. In this region the maximal stresses due to the presence of gas in coal are reported.

At that zone severe fracturing occurs, too, which further enhances the risk of an outburst.