Experimental study on the rupture process and hydraulic pressure critical condition about two kinds of typical raw coal sample loaded by high pressure water

Hard and soft coal raw samples of the same coal mine are manufactured successfully with “twice moulding”, The rupture process of two typical raw coal sample are studied with self-designed “simulation experiment device about the rupture process of raw coal samples containing gas loaded by high pressure water”. Research results show that under the action of high pressure water, brittle deformation appears to the hard raw coal samples, destruction process of “crack initiation-multiple fracturing-completely broken” occurs. Finally samples are broken absolutely, internal cracks is expanded and derived fully, extended fracture network forms, to the soft raw coal samples, plastic deformation appears internally, destruction process of “crack initiation-compaction-occlusion” occurs, samples are compacted absolutely, cracks can not be fully penetrated and extended.  © 2014 IFSA Publishing, S. L.