Research On Stope Structure Parameters And Stability Of Thick Ore Body In DaHan Gypsum Mine

Our country has an abundant gypsum mineral resource, proven reserves are approximately 8.9×1011 tons, ranking first in the world. Gypsum is the main raw material for making cement retarder and building products; at the same time, with the continuous expansion of the deep processing of gypsum products,such as the new wall materials, new waterproof materials and modification of functional materials,which indicates the increasing demand of gypsum and also the promising development market.On account of the benefit of gypsum is low, most of the gypsum mines in China adopt room-and-pillar mining method that reserves roof-protection layer and bottom-protection layer of gypsum and only a few mines use cut-and-filling mining method and caving method. But for specific occurrence conditions of ore deposit and then choice of the reasonable elements of stop and the management of ground pressure and thus to improve the total recovery rate and increase economic benefits of mine, is particularly necessary.This paper combines the conditions of Da Han gypsum mine in Lan Ling county,Shandong province and carries research on optimization of stope structure parameters and stability of thick ore body.First of all, laboratory tests of rock mechanics obtain the basic performance parameters of rock mechanics of Da Han gypsum mine such as uniaxial compressive strength,tensile strength and shear strength etc.Secondly, on the basis of the rock mechanical parameters measured in the laboratory tests, the mechanical parameters of gypsum rock mass are calculated by using the theory of the rock mass strength.Then according to the occurrence conditions of thick ore body in Dahan gypsum mine, select the suitable layered room and pillar method, and put forward the higher production capacity and efficient bottom stope technology. Based on the mining method, using engineering experience formula, the theories of engineering mechanics,load transfer intersection line theory etc to get and optimize stope structure parameters such as the stope span, thickness of roof, pillar’s form and size and slice mining interlayer thickness etc. Moreover, by calculating the strength of pillars and pillar supporting stress, it is concluded that the pillar’s safety experience coefficient and the safety factor K value can meet the safety requirements of pillars.Finally, FLAC3 D software is adopted to simulate the obtained stope structureparameters, through which the layered stope stability is analyzed not only after mining, but also after pillar has fractured, and also analyzed the influence of one collapsed stope on adjacent stope, which has proved the applicability of the stope structure parameters and the rationality of isolation pillar size, it is implied that the stratified room and pillar mining method is applicable to thick gypsum ore deposits.