Numerical study on the fracture characteristics and failure mode of hard coal under coupled static and dynamic loads

¹ School of Civil, Mining and Environmental Engineering, University of Wollongong, NSW 2522, Australia
² School of Civil and Environmental Engineering, University of Science and Technology, Beijing 100083, China

^* Corresponding author: tren@uow.edu.au
^† Corresponding author: xy987@uowmail.edu.au

Abstract

It has been well accepted by mining researchers that coal tends to undergo abrupt fracture under the coupling effect of dynamic and static loads. Hence, the study of influence of coupled static and dynamic loads on coal failure behaviour is meaningful for the understanding of coal burst. In this paper, PFC modelling of SHPB test is adopted to investigate the fracture mode and energy evolution of Australian hard coal under different combinations of pre-stress levels and impact velocities. Results have shown that high dynamic load will make the fracture mode and energy release of coal samples more violent even the static load is low. Although the strain energy increases with pre-stress level, the kinetic energy remains on a low level with the increase of pre-stress level when the impact velocity is 4 m/s.