Systems of Rock Blasting as a Rockburst Measure in the Czech Part of Upper Silesian Coal Basin

Rockbursts represent a traditional mining problem in Ostrava-Karvina coalfield (hereafter OKR). The rockburst danger connects to specific geological properties of the rockmass. The lower part of the Karvina sedimentary formation is composed predominantly of conglomerates and sandstones (their uniaxial compressive strength is approximately 100 MPa). The very high level of stress is usually concentrated in sandstone beds during the coal seams excavation. Special systems of blasting leading up to disintegration of the sandstones beds in the roof and/or to stress release in them is applied. This paper describes the applied blasting systems and discusses the obtained results.