## 1 Introduction
In addition, it cannot analyze the stress and strain of the slope during the failure process. In summary, there are some critical issues that must be addressed when these numerical methods are used to simulate progressive slope failure. (1) The DEM is time-consuming and the performance of the DEM is usually limited by computing capacity. Thus, the application of DEM in large-scale engineering is limited, i.e., when analyzing the deformation and failure of a large-scale slope, the DEM is quite computationally expensive or may even fail. (2) In the MPM, there is a strong disturbance of the particle stress and cell-crossing noise when the particles pass through the background mesh, resulting in numerical instability when the MPM is used to simulate large-scale rock slope. (3) Both the FEM and FDM are mesh-dependent. When meshes undergo a large deformation, mesh-dependent numerical simulation methods experience problems, such as a distorted mesh, i.e., when the FEM or FDM is used to simulate progressive slope failure, the problem of mesh distortion will appear, making the calculation impossible. To specifically address the above problems, in this paper, the finite difference modeling method using the adaptive local remeshing technique (LREM) is proposed to analyze and predict the process of a progressive slope failure induced by sublevel caving mining. In the proposed LREM, (1) on the basis of the slip surface determined by the maximum shear strain increment belt method, the zone of the distorted mesh is identified adaptively and the landslide body is removed; (2) the updated mesh is regenerated by the local remeshing technique and the physical field variables of the original computational model are transferred to the regenerated computational model. The novelty of the proposed method is that (1) compared with the DEM, the proposed LREM is capable of simulating progressive slope failure in large-scale rock slopes; (2) the proposed method is able to address the problem of mesh distortion in conventional FDM modeling and prevent numerical modeling from non-convergence; and (3) the proposed method regenerates the distorted meshes and part of the available meshes, resulting in a slight decrease in accuracy. However, compared with the errors induced by frequent updating of the mesh of the entire model, the adaptive local remeshing technique effectively reduces the errors. The main contributions of this paper can be summarized as follows:  
(1) The LREM is proposed to simulate the progressive failure of a simplified slope induced by sublevel saving mining, and its results are compared with those acquired using the SRM and FDM, which can verify the effectiveness of the LREM. (2) The slope failure of the Yanqianshan Iron Mine is analyzed and predicted using the proposed method, which can be applied as a reference for the sublevel saving mining plan of this mine. The rest of this paper is organized as follows. Section 2 introduces the analysis and conclusion of slope failure due to the sublevel saving mining from previous researches. Section 3 introduces the proposed method in detail. In Section 5, the proposed method is applied to simulate the slope failure of a real iron mine. Section 6 discusses the advantages and shortcomings of the proposed method. Section 7 draws several conclusions.