Investigation of Coal Failure under Triaxial Compression by CT Scanning
In order to reveal the deformation and failure mechanism of coals, the evolution of coal’s inner structures should be discovered and studied. A serial of coal specimen collected from 600m deep underground mine were scanned by a μCT system before and after conventional triaxial compression testing respectively. All the CT images were enhanced by some digital image processing techniques and then collected together to reconstructed 3D models by self-developed software. The stress-strain curves of coals at different confining pressure were obtained, and correspondingly the evolution of the inner structure of coals were well presented by enhanced CT images. Experimental results indicate that the strength of coal agrees well to linear Mohr-Coulomb Criterion. CT images show that more cracks occurs with the increasing confining pressure. It was inferred that the damage become more severe with increasing confining pressure and cause the variation of failure from ductile style at low confining pressure to brittle style at high confining pressure.
R. D. Peng et al., "Investigation of Coal Failure under Triaxial Compression by CT Scanning", Advanced Materials Research, Vols. 588-589, pp. 1903-1909, 2012