Research on the safety control technology of gob-side entry in inclined thick coal seam

Abstract

To study the safety control technology of the gob-side entry in an inclined thick coal seam, the asymmetric deformation characteristics and control mechanism of the gob-side entry in an inclined thick coal seam were analysed by combining theoretical analyses, numerical simulations and field monitoring with the prototype of a gob-side entry in a deep inclined thick coal seam in a high gas mine in Xinjiang. The research results showed that the deformation of the solid coal gang and top plate is more intense than that of the narrow coal pillar gang and bottom plate. Combined with the asymmetry of deformation surrounding rock, the gob-side entry safety control technology based on a high prestressing high-strength anchor support and a reinforced support by inclined anchor cables in key areas (a zero-displacement area within the narrow coal pillar and an intense deformation area of the solid coal gang angle) is proposed. Reasonable the gob-side entry support parameters were further determined via numerical simulation experiments, and a reasonable anchor length, row spacing and spacing to maintain the stability of the gob-side entry were obtained as 2200 mm, 800 mm and 800 mm, respectively. Engineering practice showed that the adoption of the new support technology can effectively control the asymmetric large deformation of the solid coal gang and top plate, which can maintain the stability of the gob-side entry for a long period of time and ensure the safe and efficient production of coal resources in the mine.