Application and Optimization on Support Parameters for Large Span and High Coal Wall Gateway

Abstract：According to the stability control problem of No. 5105 large span and high coal wall seam gateway in Datong Tashan Mine, the paper analyzed the span and height of the gateway affected to the stability of the seam gateway. Based on the suspension theory and combined beam theory, a preliminary design was conducted on the support parameters of the gateway. The FLAC^3D numerical simulation software was applied to study the length, diameter, row distance, pre-tension and other factors of the high strength bolt and anchor affected to the support effect. An optimized design was conducted on the preliminary support plan. The site measurement of the the surface dis- placement of the surrounding rock during the gateway driving and the coal mining period were applied to evaluate the support effect. The results showed that the convergence between the two gateway sidewalls and between the roof and floor were 275 mm and 215 mm individually during the coal mining period. The combination support with the high strength bolt ＋ anchor ＋ steel mesh could effectively resist the serious mine pressure occurred by the mining activities and the gateway deformation would be effectively controlled.