Two miners were fatally injured when a pillar bump occurred during retreat mining in a southern West Virginia coal mine.The mine was operating in the Eagle seam with overmining in the No.2 Gas and Powellton seams.A co...Two miners were fatally injured when a pillar bump occurred during retreat mining in a southern West Virginia coal mine.The mine was operating in the Eagle seam with overmining in the No.2 Gas and Powellton seams.A coal bump is defined as a sudden and violent failure of coal caused by the release of stored strain energy in the pillar.While significant strides have been made by academia,industry,and regulatory agencies to better understand bump conditions and mitigation techniques,coal bumps represent a long standing,highly site-specific engineering problem in which the exact failure mechanism is not clearly understood.In this case history,a cut-by-cut analysis of retreat mining operations was conducted on the 4 East Main leading up to the pillar bump event.Numerical input parameters were derived from site-specific geologic information and mine geometry for the analysis of pillar stress conditions and energy release using LaModel.An overview of stress conditions in the panel was presented including a precursor event that occurred two crosscuts inby the bump site.The methodology presented in the paper for the evaluation of the fatal bump event can be used for the identification of bump prone conditions prior to development and retreat of a mining area.展开更多
The development of a multiple level underground mine is a complex task in which geology,engineering,ground control,and unit operations are integrated into a single mine design.The components are interdependent and mus...The development of a multiple level underground mine is a complex task in which geology,engineering,ground control,and unit operations are integrated into a single mine design.The components are interdependent and must function cohesively to ensure a profitable underground mining operation.To optimize reserve recovery,mine planning should begin from the lowest level and progress up.This limits any misjudgments or oversights of a given level affecting the underlying levels and ensures the ability to maximize recovery from each level.Mine planning should start with the exploration and characterization of the geologic setting.Once the reserve geology and quality is well understood,then mine planning can begin with respect to the following:(1)orientation of mine works with respect to horizontal stress;(2)access to the reserve;(3)determination of opening widths;(4)selection of back,floor horizons and pillar centers;(5)selection of development and secondary mining heights;(6)appropriate inter-burden thicknesses;and(7)examining the stability of the multiple level mine through numerical modeling.The multiple level mine design process and decisions are presented through a case history example.The theme is that there is one opportunity to"get it right"and many chances to overlook a small aspect within the design that will plague the mine throughout all levels and through the entirety of its operating life.展开更多
基金The authors would like to acknowledge Mr. Eric Legg and Mr.Gary Hensley who were fatally injured during the coal pillar bumpthat occurred on May 12, 2014 on the No. 1 Section in the 4 EastMain of Brody No. 1 Mine. May the continued analysis of the BrodyNo. 1 Mine bring the industry closer to understanding the coal pillarbump failure mechanism such that further loss of life can beprevented.
文摘Two miners were fatally injured when a pillar bump occurred during retreat mining in a southern West Virginia coal mine.The mine was operating in the Eagle seam with overmining in the No.2 Gas and Powellton seams.A coal bump is defined as a sudden and violent failure of coal caused by the release of stored strain energy in the pillar.While significant strides have been made by academia,industry,and regulatory agencies to better understand bump conditions and mitigation techniques,coal bumps represent a long standing,highly site-specific engineering problem in which the exact failure mechanism is not clearly understood.In this case history,a cut-by-cut analysis of retreat mining operations was conducted on the 4 East Main leading up to the pillar bump event.Numerical input parameters were derived from site-specific geologic information and mine geometry for the analysis of pillar stress conditions and energy release using LaModel.An overview of stress conditions in the panel was presented including a precursor event that occurred two crosscuts inby the bump site.The methodology presented in the paper for the evaluation of the fatal bump event can be used for the identification of bump prone conditions prior to development and retreat of a mining area.
文摘The development of a multiple level underground mine is a complex task in which geology,engineering,ground control,and unit operations are integrated into a single mine design.The components are interdependent and must function cohesively to ensure a profitable underground mining operation.To optimize reserve recovery,mine planning should begin from the lowest level and progress up.This limits any misjudgments or oversights of a given level affecting the underlying levels and ensures the ability to maximize recovery from each level.Mine planning should start with the exploration and characterization of the geologic setting.Once the reserve geology and quality is well understood,then mine planning can begin with respect to the following:(1)orientation of mine works with respect to horizontal stress;(2)access to the reserve;(3)determination of opening widths;(4)selection of back,floor horizons and pillar centers;(5)selection of development and secondary mining heights;(6)appropriate inter-burden thicknesses;and(7)examining the stability of the multiple level mine through numerical modeling.The multiple level mine design process and decisions are presented through a case history example.The theme is that there is one opportunity to"get it right"and many chances to overlook a small aspect within the design that will plague the mine throughout all levels and through the entirety of its operating life.
