Abstract: To study the stability of stopes in an underground mine, an approach to analyze the stability of irregular ore pillar was established on the basis of Voronoi diagram. Taking Dayin’gezhuang Gold Mine as engineering background, the collapse modes of ore pillars and roofs were investigated and analyzed, and the main factors influencing pillar stability was put forward. In addition, orthogonal polar difference analysis was used to investigate the sensitivity of influencing factors, and the affecting sequence was listed from the most to minor. The stability status of ore pillars at -496m level were evaluated, and the results show that the safety coefficients of No.1-2, No.2-6, No.3-1, No.3-2 and No.4-2 ore pillars are all below 1.0. The stability of No.6203 Stope is the worst, and the pillars are extremely vulnerable to failure contiguously. Finally, support control measures were taken to ensure the stope stability. It is proved that the occurrence of roof caving and ore pillar fracturing is rapidly decreased, and the whole safety of mining stop is significantly improved.

Key words: Voronoi diagram, underground stope, stability, control technique