ABSTRACT
ABSTRACT: On the basis of the monitoring results of columnar jointed basalt rock stress and strain deformation, this study investigated the evolution of rock loosening deformation and deformation mechanism and established a surrounding rock safety evaluation system by using energy rate and unit deformation force. This study shows that the stability of columnar jointed basalt is poor and the surrounding rock deformation decreases with the increase in depth. Excavation with support construction methods helps control the deformation of the convergence range, pre-splitting blasting helps control the deformation of surrounding rock, and excavation without support and pre-split blasting is not conducive to the control of the deformation convergence range. Invading surrounding rock formed an arch after the columnar jointed basalt rock was supported; it is conducive to the absorption of surrounding rock deformation energy released. Pre-splitting blasting can effectively prevent the deformation of surrounding rock in shallow joints, but not conducive to the control of the late surrounding rock deformation associated with hidden joints deformed. Excavation is conducive to the release of the energy generated by shallow surrounding rock joint deformation; timely support can help control the energy generated by hidden joint deformation produced by surrounding rock deformation. Energy rate and unit deformation force can effectively evaluate the security characteristics of columnar jointed basalt wall rock.
