###### Abstract
Second, the barrier effect of rock mass movement caused by faults is not clearly understand, which will lead to the unreasonable design of underground mine shafts and roadway engineering, resulting in the abandonment of some shaft and roadway engineering, and will significantly affect the safe, effective, and environmentally friendly mining of mines. In China, the safety production of metal mines still maintains a severe situation. On the premise of advocating safe and efficient production, it is vital to do research on the related problems faced in the mining process of underground metal mines. Therefore, based on the key factors such as the distance between the fault and the mining area, the buried depth of the fault of the upper boundary, the fault dip angle, the size of the mining area, and the fault fracture zone thickness, this paper studies the fault activation and its influencing factors on the barrier effect of rock mass movement under the influence of mining. Analysis of the Fault Activation and Its Influencing Factors on the Barrier Effect of Rock Mass Movement under the Influence of Mining  
If there is a fault in the surrounding rock of the mining area, it will affect the characteristics of the stress field and displacement field caused by excavation, thus causing changes in the potential energy of the rock mass within a certain range. In the process of this change, the work done by the rock mass's own gravity, on the one hand, is consumed in the friction action and slip deformation of the fault, and at the same time, it causes the discontinuous distribution of the displacement field and stress field of the rock on both sides of the fault. On the other hand, it also causes the surrounding rock in the excavation area near the fault to have the characteristics of large displacement and high-stress difference, so that the overall geometric and physical symmetry is destroyed. On the contrary, various influencing factors in the process of underground mining will also cause rock mass movement, destruction, deformation, etc., which will cause the dislocation of originally stable faults, which is called \"fault activation.\" It is found that in the process of large-scale underground mining, faults distributed within the mining influence range will become barriers for rock mass movement, deformation, and mining stress transmission, and many adverse underground phenomena are related to this barrier mechanism. Therefore, this paper studies the factors affecting fault activation and its barrier effect. The strength of fault activation and its barrier effect on rock mass movement is mainly determined by several key factors, such as the distance (location) from the fault to the mining area, the fault's buried depth of the upper boundary, the fault dip angle, the size of the mining area and the fault fracture zone thickness. A large three-dimensional discrete element numerical simulation software 3 DEC is used in the model calculation of this paper. The size of the numerical calculation model is 1600 m along the X direction, 50 m along the Y direction, and 800 m along the Z direction. The model is divided by a regular tetrahedron grid. In order to ensure the calculation accuracy, the grid around the fault and the mining area has been densified. The entire model is divided into 688,719 grids, the maximum side length of the model grid is about 9 m, and the minimum side length is about 1 m. Since the minimum excavation size is 50 m \(\times\) 100 m, according to the trial calculation result and previous calculation experience, the accuracy of the model grid can meet the calculation requirements. During the calculation, the horizontal displacement is constrained on both sides and the front and rear boundaries of the model, the bottom boundary of the model is constrained to all displacement, and the upper boundary of the model is a free surface. The parameters of numerical simulation calculation are shown in Table 1[52].