Instability of a coal pillar section located at a steep mining face: Pillar size selection
2013; Elsevier BV; Linguagem: Inglês
ISSN
2212-4578
Autores Tópico(s)Rock Mechanics and Modeling
ResumoTheoretical analysis,numerical simulations,and field measurements were used to analyze the distortion and stability of a coal pillar located in a steep mining face.The surrounding stress and goaf caving and back filling methods were investigated.Different cross-sectional dimensions and pillar angles were examined.The results show that step-type failure is the predominant failure mode of the pillar.The instability of the pillar from the effects of shear stress is given by α≥arctan(f1+f2).The failure mode is sliding along the working face in a region located at the lower end floor and the upper end roof.The field conditions in the Xintie mine of the Long Mine group,located at the Qitaihe branch were examined.Increasing the coal pillar cross sectional area or strengthening by grouting and back filling at the rear of the goaf above the pillar were suggested.These approaches allowed safe,fully-mechanized face mining in the steep seam.
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