Influence Of Deep Mining On Stability Of Shallow Goaf And Shaft Impact Study

Ore resources are not only the material basis for human survival,but also an important guarantee for social and economic development.However,the long-term arbitrary excavation has exhausted the shallow ore resources.In order to meet people’s increasingly strong demand for ore resources,deep mining has become a new form of ore resource development.However,in the process of deep ore body excavation,the mining of deep ore blocks often leads to the occurrence of disasters such as shallow goaf instability and shaft deformation and fracture,which has caused irreparable economic losses and casualties to mining enterprises.Therefore,the analysis and study of the impact of deep mining on the stability of shallow goaf and shaft is of great significance to ensure the safety of mine production.Taking xindadong Baishu gold mine in Baotou City as the research background,this paper takes the impact of deep mining on the stability of shallow goaf and upper and lower wall shaft as the main research goal,and focuses on the impact of 188m～-300 m sublevel open stope mining and sublevel open stope subsequent filling mining of No.32 ore body of xindadong Baishu gold mine on the stability of shallow goaf of No.32 ore body,shallow goaf of No.13 ore body and upper and lower wall shaft,The research results obtained in this paper are as follows:(1)The rock samples are collected in the field and made into test pieces required for the test.The physical and mechanical parameters of various rocks are measured through various indoor rock mechanics tests.Secondly,the rock mechanics parameters obtained from the test are modified and reduced by using the generalized Hoek Brown criterion.After comprehensive analysis,the mechanical parameters of the rock mass of Xinda dongbaishu gold mine are obtained.(2)Some softwares are used to establish the three-dimensional mine model of xindadong Baishu gold mine,and FLAC3 D software is used to simulate the open stope method to mine different middle sections of 188 m ～ 300 m of No.32 ore body.According to the obtained stress,displacement and plasticity of goaf and shaft,the cloud distribution diagram is distinguished,and the stability of goaf and shaft and the areas prone to deformation and failure are analyzed.The analysis results show that in the process of sublevel open stope mining,the goaf of No.13 ore body is less affected by disturbance,the degree of stress concentration in the goaf is relatively small,and the displacement of roof and pillar is also relatively small;The excavation of ore body has a great impact on the stability of the goaf of No.32 ore body.The pillar,roof and floor in the goaf have been greatly displaced and some have been damaged.The stress concentration in the goaf is obvious and the stability of the goaf is poor;In the process of sublevel open pit mining,the deformation of the hanging wall shaft is within the controllable range,but the deformation of the footwall shaft has exceeded the specified safety range.(3)The 188m～-300 m goaf of No.32 ore body is simulated by using FLAC3 D software.The simulation results are compared with the plastic zone,minimum principal stress,maximum principal stress and so on.In the mining process of sublevel open stope subsequent filling method,the distribution range of plastic zone in the goaf of No.32 ore body is significantly reduced,the stress concentration in the goaf is significantly improved,the displacement of pillar and roof is greatly reduced,and the deformation of upper and lower wall shaft meets the safety regulations,indicating that the scheme of sublevel open stope subsequent filling method is more reasonable and can ensure the stability of goaf and shaft in the mining process,The achievements provide a theoretical basis and basis for the selection of deep mining scheme and the treatment method of goaf.