Development of physical model test system for fault-slip induced rockburst in underground coal mining

Abstract

A complex geological environment with faults can be encountered in the process of coal mining. Fault activation can cause instantaneous structure slipping, releasing a significant amount of elastic strain energy during underground coal mining. This would trigger strong rockburst disasters. To understand the occurrence of fault-slip induced rockbursts, we developed a physical model test system for fault-slip induced rockbursts in coal mine drifts. The boundary energy storage (BES) loading apparatus and bottom rapid retraction (BRR) apparatus are designed to realize energy compensation and continuous boundary stress transfer of the surrounding rocks for instantaneous fault slip, as well as to provide space for the potential fault slip. Taking the typical fault-slip induced rockburst in the Xinjulong Coal Mine, China, as the background, we conducted a model test using the test system. The deformation and stress in the rock surrounding the drift and the support unit force during fault slip are analyzed. The deformation and failure characteristics and dynamic responses of drifts under fault-slip induced rockbursts are obtained. The test results illustrate the rationality and effectiveness of the test system. Finally, corresponding recommendations and prospects are proposed based on our findings.