Failure of mine pillars,especially in deep underground mines,significantly threatens the safety of miners and equipment.Previous studies on mine pillar stability design have used classical constitutive models that ign...Failure of mine pillars,especially in deep underground mines,significantly threatens the safety of miners and equipment.Previous studies on mine pillar stability design have used classical constitutive models that ignore the intermediate principal stress component when determining the factor of safety.In this study,we develop and implement a three-dimensional modified Hoek-Brown(HB)constitutive model that incorporates the intermediate principal stress component into the numerical simulation tool FLAC3D.Furthermore,we propose and apply a strength-reduction technique to determine a more accurate factor of safety for mine pillars.This novel approach provides a more comprehensive and realistic method for geomechanical analysis and pillar design,enhancing our understanding of pillar stability.Through numerical analysis,we illustrate the impact of the intermediate principal stress component on mine pillar plasticity.The factor of safety is calculated via the strength reduction method,revealing a substantial improvement from 1.7 with the classical HB model to 2.0 with the 3D HB model.Including the intermediate principal stress component reduces the evolution of plasticity in the mine pillar.For instance,the volume of plastic zones diminishes,and the factor of safety increases as the width-to-height ratio increases.Exemplary simulations show that ignoring the effect of the intermediate principal stress component,including underestimating safety levels,designing suboptimal pillar design,and misinterpreting in situ observations and measurements,can lead to severe consequences.展开更多
文摘Failure of mine pillars,especially in deep underground mines,significantly threatens the safety of miners and equipment.Previous studies on mine pillar stability design have used classical constitutive models that ignore the intermediate principal stress component when determining the factor of safety.In this study,we develop and implement a three-dimensional modified Hoek-Brown(HB)constitutive model that incorporates the intermediate principal stress component into the numerical simulation tool FLAC3D.Furthermore,we propose and apply a strength-reduction technique to determine a more accurate factor of safety for mine pillars.This novel approach provides a more comprehensive and realistic method for geomechanical analysis and pillar design,enhancing our understanding of pillar stability.Through numerical analysis,we illustrate the impact of the intermediate principal stress component on mine pillar plasticity.The factor of safety is calculated via the strength reduction method,revealing a substantial improvement from 1.7 with the classical HB model to 2.0 with the 3D HB model.Including the intermediate principal stress component reduces the evolution of plasticity in the mine pillar.For instance,the volume of plastic zones diminishes,and the factor of safety increases as the width-to-height ratio increases.Exemplary simulations show that ignoring the effect of the intermediate principal stress component,including underestimating safety levels,designing suboptimal pillar design,and misinterpreting in situ observations and measurements,can lead to severe consequences.
