Mining Structure Parameters Optimization Design Of Stope And Analysis On The Stability Of Surrounding Rock In Baixiangshan Iron Mine

The construction and mining of a complicated water-rich iron mine is often endangered byroof instability of surrounding rock. So, How to adopt rational mining structure parameters andmining schemethe to ensure stope security is a difficult problem which desiderates to be solvedeffectively as soon as possible. Relying on the “the development and study on the crucialtechnology of exploring the complicated water-rich mine”, one of the national “11th Five-Year”science and technology supporting projects, the thesis has researched intensively on thegeohydrologic conditions and the indoor rock experiment in the typical complicated iron mine ofBaixiangshan. Using Hoek-Borwn strength criterion to determine the western large and thickorebody physical parameters, at the same time, by using FLAC3D numerical analysis softwareestablishes different mining spans, access widths and layered mining heights throughthree-dimensional numerical model. The thesis has explored and studied the stope roof stabilityunder the condition of different mining spans, access widths and layered mining heights. Theabove research can provide the theoretical and practical directive function for adoptingrational mining structure parameters and mining scheme of the water-rich deposit. The mainworks and contents are as followed:(1) Based on the site survey geohydrologic conditions and the rock mechanicsparameters of the indoor rock experiment in large and thick ore body in western ofBaixiangshan, using RMR classification method determines the rock mass quality level of oremining area.(2) In the premise of using RMR classification method to determine the RMR ratingvalue of the large and thick ore body in western of Baixiangshan, and considering the impactof blasting process on the rock mass disturbances, thus introduce perturbation parameter D.On this basis, using Hoek-Borwn strength criterion determines the rock mass mechanicparameters of large and thick ore body in western of Baixiangshan.(3) Combined with the specific geological conditions of the large and thick ore body inwestern of Baixiangshan, on the background of filling mining under strip pressure and drainingdry locally in underlayer, selected the representative region with the instability strip and“scuttle” which is between north of the exploration line1and south of the exploration line9asthe orebody mining geologic model, establishes a three dimensional numerical model under thecondition of seepage condition. According to the orthogonal experimental design methods, themining simulation solutions of nine stope structural parameters which contain different miningspans, access widths and layered mining heights are formulated. The valuation of the stability ofthe mining roof is marked by the largest settlement, the maximum tension stress, the maximumvolume of the plastic zone and the situation of plastic zone through. Finally, the best mining structure parameters are confirmed by different simulated results.(4) Based on the mining conditions of the optimized and determined stope structureparameters, through researching and analyzing the roof stability of surrounding rock of numericalsimulation under the condition of different mining sequence, burial depth and roof thickness,quested and analyzed the influence of different mining sequence, burial depth and roof thicknessof the stability of surrounding rock of the stope.