Author details

6. Progress of the failure in different pillar ratios

Figure 6. Failure mode of a single pillar with the different w/h ratios.

Elastic strain energy (kJ/m<sup>3</sup>

)

Dissipated elastic strain energy (kJ/m<sup>3</sup>

220 Finite Element Method - Simulation, Numerical Analysis and Solution Techniques

)

Ratio (w/h) 3DEC Analytic 3DEC Analytic 3DEC Analytic 3DEC Analytic 2.58 2.65 1.767 1.55 4.91 4.77 14.87 14.77 1.5 2.94 2.37 1.88 0.78 8.88 8.46 16.56 15.23 4.24 4.01 2.891 2.92 12.55 11.98 21.23 20.14 2.5 6.72 6.84 3.18 3.11 15.37 15.41 24.35 23.99 13.15 12.62 5.51 5.44 37.15 36.87 28.45 27.68 16.76 16.27 7.07 7.20 60.26 62.33 59.11 57.88 19.83 19.28 8.334 8.22 76.22 75.12 96.54 92.66

The amount of the energy in the pre-peak stage (kJ/m<sup>3</sup>

)

The energy released in the post-peak stage (kJ/m3

)

Different loading conditions varying from the quasi-static to dynamic loading has been applied to the coal pillar with the different width to height (w/h) ratio to determine the pillar capability as well as the possible observed failure modes. A strain-based criterion, as a major failure criterion, was implemented in the ABAQUS/Explicit to predict of the cracking path due to the different applied loadings as well as different pillar geometrical properties. A quarter

Table 2. A comparison between the different energy components (3DEC and the analytical solution).

Faham Tahmasebinia\*, Chengguo Zhang, Ismet Canbulat, Onur Vardar and Serkan Saydam \*Address all correspondence to: faham.tahmasebinia@sydney.edu.au School of Mining Engineering, University of New South Wales, Sydney, Australia
