Energy relief effect of real-time drilling to prevent rockburst in high-stress rock
Zhichao He, Fengqiang Gong, Li Ren, Weimin Yang, Xuezhen Wu
Abstract
To investigate the energy relief effect of real-time drilling in preventing rockburst in high-stress rock, a series of high-stress real-time drilling uniaxial compression tests were conducted on red sandstone specimens using the SG4500 drilling rig. Results showed that the mechanical behavior (i.e. peak strength and rockburst intensity) of the rock was weakened under high-stress real-time drilling and exhibited a downward trend as the drilling diameter increased. The real-time drilling energy dissipation index ( E RD ) was proposed to characterize the energy relief during high-stress real-time drilling. The E RD exhibited a linear increase with the real-time drilling diameter. Furthermore, the elastic strain energy of post-drilling rock showed a linear relationship with the square of stress across different stress levels, which also applied to the peak elastic strain energy and the square of peak stress. This finding reveals the intrinsic link between the weakening effect of peak elastic strain energy and peak strength due to high-stress real-time drilling, confirming the consistency between energy relief and pressure relief effects. By establishing relationships among rockburst proneness, peak elastic strain energy, and peak strength, it was demonstrated that high-stress real-time drilling reduces rockburst proneness through energy dissipation. Specifically, both peak elastic strain energy and rockburst proneness decreased with larger drill bit diameters, consistent with reductions in peak strength, rockburst intensity, and fractal dimensions of high-stress real-time drilled rock. These results validate the energy relief mechanism of real-time drilling in mitigating rockburst risks.