Pillar stability is one of important aspects for underground mines.Generally,the stability of the pillars is evaluated empirically based on case studies and site-specific rock mass conditions in mines.Nevertheless the...Pillar stability is one of important aspects for underground mines.Generally,the stability of the pillars is evaluated empirically based on case studies and site-specific rock mass conditions in mines.Nevertheless the empirical approach applicability can sometimes be constrained.The numerical-based approaches are potentially more useful as parametric studies can be undertaken and,if calibrated,can be more representative.Both empirical and numerical approaches are dependent on the strength evaluation of the pillars while the strain developing in the pillars is seldom taken into consideration.In this paper,gypsum and sandstone samples were tested in laboratory with different width-to-height ratios (W/H) to adapt the strain evaluation method to the laboratory-based pillars.A correlation was then developed between the strain and the width-to-height ratio for pillar monitoring purposes.Based on the results,a flowchart was created to conduct back analysis for the existing pillars to evaluate their stability and design new pillars,considering the strain analysis of the existing pillars with the W/H ratios modelled.展开更多
This paper presents results which concern regularities of propagation of discontinuous zones from mined-out space in rock massif with inclined bedding structure. The dependencies of maximal height of these zones from ...This paper presents results which concern regularities of propagation of discontinuous zones from mined-out space in rock massif with inclined bedding structure. The dependencies of maximal height of these zones from the inclination angle of productive beds were found. The mechanical model of rock massif was chosen as viscoelastic and transversely isotropic. Finite element method was used for calculation performing. Coulumb-Mohr and maximal elongation criteria were used for determination of discontinuous zones.展开更多
文摘Pillar stability is one of important aspects for underground mines.Generally,the stability of the pillars is evaluated empirically based on case studies and site-specific rock mass conditions in mines.Nevertheless the empirical approach applicability can sometimes be constrained.The numerical-based approaches are potentially more useful as parametric studies can be undertaken and,if calibrated,can be more representative.Both empirical and numerical approaches are dependent on the strength evaluation of the pillars while the strain developing in the pillars is seldom taken into consideration.In this paper,gypsum and sandstone samples were tested in laboratory with different width-to-height ratios (W/H) to adapt the strain evaluation method to the laboratory-based pillars.A correlation was then developed between the strain and the width-to-height ratio for pillar monitoring purposes.Based on the results,a flowchart was created to conduct back analysis for the existing pillars to evaluate their stability and design new pillars,considering the strain analysis of the existing pillars with the W/H ratios modelled.
文摘This paper presents results which concern regularities of propagation of discontinuous zones from mined-out space in rock massif with inclined bedding structure. The dependencies of maximal height of these zones from the inclination angle of productive beds were found. The mechanical model of rock massif was chosen as viscoelastic and transversely isotropic. Finite element method was used for calculation performing. Coulumb-Mohr and maximal elongation criteria were used for determination of discontinuous zones.
文摘分析了碎屑结构煤系地层岩体变形破坏的岩体力学特征及断裂带导水机理,认为岩体体积扩容是工作面顶板破坏内导水性增强、形成导水断裂带的根本原因.应用FLAC3D模拟分析了连续介质、大变形条件下急倾斜特厚煤层开采引起的覆岩体积应变分区特征,分为连续介质条件下的内部塑性破坏-压缩区、扩容区及外部弹性压缩区.依据垮落带形成过程中的体积变化特征,将连续介质条件下获得的内部塑性破坏-压缩区划为垮落带;扩容区划为断裂带;以分隔扩容区与外部弹性压缩区的体积应变0等值线最大高度确定防水煤柱高度.此方法应用于开滦赵各庄2137急倾斜特厚煤层开采工作面,确定上部防水煤柱高度为63.8 m.
