Buckling mechanism of pillar rockbursts in underground hard rock mining

ABSTRACT

The objective of this paper is to investigate the buckling mechanism of pillar rockbursts in underground hard rock mines from an innovative point of view. By considering rockbursts as a buckling (instability) problem of structures, rockbursts are classified into three categories: induced rockburst, triggered rockburst and inherent rockburst, in accordance with the magnitude of the dynamic stimulation force from large to null. Rigorous mathematical models are set up for these three rockbursts. For induced and triggered rockbursts, mechanism of parametric resonance is found and perturbation effect is observed. For inherent rockbursts, the condition of critical static loads is obtained. Various examples of rockbursts in Dongguashan Copper Mine are analysed. The limitations of the approach are addressed. Contrary to conventional methods where only rock materials or rock specimens were used for investigation of rockbursts, this study attaches more attention on the structural effect on rockbursts, which may appeal to practising engineers.

KEYWORDS:

• Underground mining
• hard rock
• pillar
• rockburst
• buckling
• instability

Acknowledgements

The geological materials of Dongguashan Copper Mine mentioned in Section 3.5 were provided by Tongling Nonferrous Metals Co. Ltd to the second author. Discussions with Professors C.L. Pan, L.G. Wang and F.C. Zhu at CSU were greatly appreciated.

Disclosure statement

No potential conflict of interest was reported by the authors.