7. Remarkable conclusions

Analytical method is an important part of coal burst evaluation and forecasting. Analytical forecasting methods, either alone or combined with numerical simulations, can be used to estimate both in situ stress and induced stress, which leads to the prediction of failure-prone areas and calculation of critical values of the energies. The behaviour of a single pillar under different applied loads ranging from the quasi-static towards the dynamic loading conditions was simulated using commercial finite element package ABAQUS/Explicit. A strain-based failure condition was evaluated to determine the failure modes in a single pillar by respecting to the different w/h ratios. The observed numerical failure modes can be classified by shear and compression failures as well as a combination of both shear and compression were comprehensively illustrated. The released energy or residual energy is either transferred into kinetic energy or dissipated energy in non-elastic behaviour such as joint shear and fracturing. The unstable release of potential energy of the coal around the excavations, mainly in the form of kinetic energy, causes coal burst.
