Study on the evolution and prediction of fracture depth of surrounding rock in deep mining roadway based on numerical analysis and borehole detection

Abstract

The failure of surrounding rock in deep hard rock roadway is closely related to mining disturbance. In this study, the 13# stope ramp of −767 m level (at a buried depth of 1,197 m) at Hongtoushan copper mine was taken as the engineering background, a comprehensive analysis method of numerical analysis and borehole detection was put forward, and the evolution law of fracture depth of the ramp surrounding rock under the mining influence was obtained. The results show that the maximum tangential stress and fracture depth of the ramp surrounding rock on both sidewalls increase slowly at the initial mining stage. When the ore body above the ramp is mined, the maximum tangential stress and fracture depth of the ramp surrounding rock on both sidewalls increase rapidly, and the two parameters are positively correlated. Based on this, the ratio of the maximum tangential stress of the surrounding rock to the uniaxial compressive strength of intact rock (σθmax/σc) and the equivalent radius (a) of the roadway were used as parameters, and an equation for the fracture depth of the roadway surrounding rock was proposed. Through the case analysis, the results show that the proposed equation of fracture depth of the roadway surrounding rock has good prediction accuracy. This study enriches the research on the stability and failure mechanism of the roadway surrounding rock under the mining disturbance, and provides new basis for the support design of mining roadways.

Stability mechanisms of soft rock mining roadways through roof cutting and pressure relief: an exploratory model experiment

“…The numerical model includes coal pillars and two gobs, and the inclination angle of the coal formation is 6°(Figure 17A). To improve the calculation accuracy, the grid near the roadway is densified (Li et al, 2022b). The constitutive model is the Mohr-Coulomb model (Li et al, 2022c;Najm and Daraei, 2023).…”

Stability assessment of surrounding rock in downward mining route supported by slab-wall backfill structure

“…Ground pressure becomes one of the major contributors to geological hazards in mining stopes, consisting mainly of the pressure acting on roof, pillars, surrounding rock, and back ll [1][2][3]. Varying sequences of excavation and back ll result in diverse pressure patterns within the stope [4,5]. Stress concentration and stress reduction areas emerge within speci c excavation zones, leading to deformation, movement, and damage of the surrounding rock, ultimately impacting stope stability.…”

Application of Ground-Penetrating Radar with the Logging Data Constraint in the Detection of Fractured Rock Mass in Dazu Rock Carvings, Chongqing, China

“…Various geophysical methods have been applied for fissure detection, such as Ground-Penetrating Radar (GPR) [3,4], electrical prospecting [5,6], electromagnetic prospecting [7], Nuclear Magnetic Resonance (NMR) [8,9], acoustic exploration [10,11], CT scanning [12,13], and comprehensive logging [14,15]. However, these methods are rarely applied to detect fissures in rock cultural relics; they are mostly used for fissures in reservoir rock mass and hydrogeological related fissures [16][17][18]. GPR is a common near-surface geophysical method with high resolution, high efficiency and non-destructiveness.…”