Abstract: To understand the sensitivity of factors influencing pillar stability, pillar arrangements in different sublevels are counted. Based on the local pillars in Dayingezhuang gold mine, pillar safety factor formulas of different forms were derived. Using six factors-five levels technology to design the experiment to analyze sensitivity of impact factors; at the same time this paper studies the relationships between pillar safety factor and pillar width, mining depth and room width. The study shows that the size of sensitivity of these factors affecting the stability of the pillar has been obtained via orthogonal experiment method and diminishes in turn : pillar width, mining depth, room width; in addition, the pillar safety factors follow the exponential function with the pillar width growth; follow power function with the mining depth decrease; and follow the exponential function with room width decrease. According to the pillar safety factor regression equation which is based on DPS and Matlab software, the minimum size of single-form pillar arrangement which satisfies both stability and security of the pillar has been reasonably obtained after analysis. Column width should be no less than 3.6 m; square column width should be 5.9 m or lager; and the room width should be no more than 8 m, which will certainly provide identifiable ground for the arrangements of pillar in deep middle section.

Key words: orthogonal experiment method, sensitivity analysis, pillars stability, safety coefficient method, regression equation