Stability Analysis And Treatment Of Underground Iron Mine Affected By Underground Water

With the rapid development of China’s national economy,the demand for natural resources is increasing,especially mineral resources although people have obtained great economic benefits in the process of mineral mining,a large number of mined-out areas have been formed due to unscientific mining or civil plundering mining.The existence of these mined-out areas makes the surrounding mineral resources unknown and cannot be mined,which affects the overall layout of underground mining production therefore,in the case of the existing old goaf,it is particularly important to study the stability of water-filled goaf,determine the reasonable location for continued mining and the goaf treatment plan.Paper to Anshan bow fault line-04 and line-06 of iron ore mining area as the research object,all in two mining area are the cases of old empty area,through field survey,structure of rock mass mechanics analysis and numerical simulation,the method of combining the two mining continues to excavation under different conditions and different spacing on the produce of multilayer goaf stability is evaluated,and according to the evaluation if the design of the goaf governance scheme paper mainly draws the following conclusions:The rock in the mining area of line-04 and line-06 belongs to the hard rock,and the surrounding rock near the old goaf belongs to "the broken area" and "the relatively broken area".After the excavation of the two numerical models,compared with the old goaf only,the surrounding rock stress on both sides of each goaf is compressive stress,and the tensile stress is distributed in the roof and floor.Compared with the cavity spacing of 10m,the maximum principal stress of the line-04 model changes from 3.4133MPa to 3.2740MPa when the cavity spacing is 15m,the maximum principal stress of the line-06 model changes from 3.8616MPa to 1.0498MPa,and both compressive stresses decrease;the minimum principal stress of the line-04 model changes from 0.0868MPa to 0.11269MPa,and the minimum principal stress of line-06 changes from 0.0678MPa to 0.1158MPa,the tensile stress increases.the strain value and the goaf area increase obviously.Rock mechanics parameters to reduce the influence of ground water has resulted in serious negative impact on cavity group,when there is multilayer goaf,the upper cavity will be harmful to the lower cavity stability.The fourth condition according to the characteristics of the working condition of the second 3 strain and the plastic zone area significantly increased,the most conducive to mining into four conditions when the spacing is set as 15 meters,the strain extreme value of the fourth working condition of the two models is small,and there is no through plastic zone between each goaf.When the safe mining spacing is 10 meters,the strain extreme value is large,and there is a continuous and wide yield zone between the goaf,which does not meet the safe mining conditions.The filling treatment of old goaf and retaining part of ore body as natural pillar during the excavation of new goaf significantly improve the stability of goaf group.When the width of natural pillar is 2 meters,the yield of pillar is left,and when the width is 4 meters,the pillar is safe and plays a better supporting role considering the high cost of filling treatment,the treatment plan of line-04 is determined to be half filling method combined with natural pillar with a width of 4 meters.The treatment scheme of line-06 model is determined to be complete filling method combined with 4meter-wide natural pillar.In this paper,the mining stability of the line-04 an line-06 mining area of Gongchangling Iron Mine and the follow-up safety management plan are deeply studied,which has practical value and certain theoretical significance for the subsequent development of iron ore resources.