Stability analysis and determination of support system in 2741 level of angouran underground mine

摘要: The stability of underground mining spaces and the analysis of stresses and deformations created after explotiation have a particular importance in underground mine designe. Anguran lead-zinc mine is located 125 kilometers southwest of Zanjan city and according to the plan, at least 12,000 tons of ore will be extracted from underground section of it. The ore in this mine consists of three rock types, including sulfur ore, carbonate, as well as a mixture of sulfur and carbonate ores. Sulfur ore mass has the highest rock mechanical strength and carbonate ore has the lowest. This research investigate the stopes stability of 2741 level in underground Angoran mine in order to obtain appropriate dimensions of stopes and to provide the necessary support using Finite Element Method. For this purpose, in both sulfur and oxidized ore zones, different dimensions and supports of the stopes are determined by comparing the displacements around the stopes with the critical and permissible strain values calculated from the Sakurai relations. The results of the analyzes based on the input data indicate the appropriate stability condition in the sulfur ore. The impact of pillar in sulfur ore was investigated for two widths of 5 and 10 m, and the results showed that in both cases, the stopes were stable without support system. But due to discontinuities in the roof and parts that are mixed with sulfur and oxidized, a support system is needed. In oxidized and mixed ores, the support system should be used because of the poor properties of the rock the dimensions of the pillar.