Numerical Simulation Study On The Influence Of Underground Mining On Surface Subsidence And Shaft Deformation In North Region Of Xiaoguanzhuang Iron Mine

Underground mining will inevitably lead to the movement and deformation of overlying strata and ground surface. Damage of sinking and driving engineering and even surface constructions will be caused once the movement and deformation exceed a certain range. Therefore, it is of great importance to research and predict the movement and deformation of ground surface caused by underground mining.On basis of summarizing the research history and status of mining subsidence, this paper described the basic rule of surface subsidence, which caused by underground mining. According to the problem induced by underground mining in Xiaoguanzhuang iron mine, which the ground surface and shaft had large movement and deformation, numerical mode was established by using ANSYS. By importing the numerical model into FLAC3D, numerical simulation of underground mining in north region of Xiaoguanzhuang iron mine was carried out in this paper.Mining in -400m stage north region of Xiaoguanzhuang iron mine was firstly simulated to calculate and determine the movement and deformation range of ground surface.Through the comparison of simulation results and field measured data, the reliability of numerical model and parameters was verified. On this basis, numerical simulation of non-pillar sublevel caving and upward drift mining with backfilling to part of the orebody within 150m range outside the safety pillar in -450m stage north region of Xiaoguanzhuang iron mine was carried out respectively. According to the result of simulation calculation, surface subsidence curve was drawn under different mining schemes. The comparison and analysis of calculation results indicate that movement and deformation of ground surface and shafts will continue to develop along with mining. While, the movement and deformation of ground surface, especially tilt deformation can be controlled with filling mining method. Finally, mining of all orebody in -450m stage was simulated. By the comparison and analysis of the simulation results of different mining schemes, we can know that if non-pillar sublevel caving was applied in -450m stage it is bound to affect the the safety of main shaft and auxiliary shaft 1#. In use of filling mining method, the movement and deformation of ground surface and shaft can be reduced effectively to ensure the safety production of Xiaoguanzhuang iron mine.Considering the factors such as the safety of ground surface and shaft, cost of filling mining and production capacity,3-zones mining model could be applied in -450m stage north region of Xiaoguanzhuang iron mine, which backfilling mining be applied to mine the orebody within 150m range outside the safety pillar in -450m stage and non-pillar sublevel caving continue to be applied to mine the other orebody.