Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1753953 | International Journal of Coal Geology | 2009 | 14 Pages |
Abstract
On the contrary, for model C, the distributions and magnitudes of horizontal and vertical stress show higher tensional stresses in both rib sides of the roof fall zone. The deformation around the dyke-induced perturbation zone affects a large volume of coal. The deformation vectors with high magnitudes are nearly horizontal and propagate laterally up to 30Â m; whereas, low-magnitude deformation vectors extend about 25Â m toward the roof and 20Â m toward the floor. The vertical tensional displacement, which is concentrated in the floor and the left and right hand sides of the roof, propagates about 30Â m on both sides and about 22Â m in the floor. From these simulation results, it is thought that the extension of the dyke-induced perturbation zone toward the roof, floor, and rib sides of the entry roadway initially creates small tensional cracks that gradually grow into large-scale tensional features. These features could also be responsible for high concentrations of gas, which are emitted into the mine from fractured coals due to insufficient mine ventilation and low atmospheric pressure.
Related Topics
Physical Sciences and Engineering
Earth and Planetary Sciences
Economic Geology
Authors
Md. Rafiqul Islam, Ryuichi Shinjo,