# Prediction of the Dangerous Range of Dumps Based on a Dynamic Process
## 1 Introduction
For example, [PERSON] studied the effects of different slope heights, slopes, and soil materials on the stability of dumps [1]. Some scholars analyzed the stability of the dump based on the mechanical parameters, stacking sequence, and substrate properties of the dump deposit, and some scholars studied the failure mode of dump slopes and claimed that there are two modes of landslides, traction landslides and push landslides in the dump. The main research methods of dump slope stability are numerical simulation analysis and model test analysis. The rigid body limit equilibrium analysis method, which originated from the rigid body limit equilibrium analysis method based on statistics, has been proven to be accurate by many projects at home and abroad, but it cannot reflect the changes in stress and strain of the slope with time. With the rapid development of computers, the finite element method and finite difference method based on elastic-plastic theory, usually combined with the strength reduction method, are widely used in slope stability calculations. For example, [PERSON] combined with strength reduction method, and a stability analysis of the dump slope structure based on numerical simulations was performed [2]. [PERSON] used the finite element method to calculate the stability of a dump and analyzed the influence of different materials on the deformation of the slope [3]. [PERSON] used the finite difference method to calculate the stability of the dump [4]. There are also discrete medium mechanics methods and meshless methods for large deformation, such as the discrete element method (DEM), discontinuous deformation analysis method (DDA), smoothed particle hydrodynamics method (SPH), and material point method (MPM). The discrete element method is a numerical analysis method proposed by [PERSON] and applied to the stability analysis of rock and soil. [PERSON] analyzed the global stability of mine waste dumps by means of discrete element simulations [5]. Due to the limitation of grids, the calculation is likely to be nonconvergent. Therefore, some meshless numerical methods are used in the analysis of large deformation problems, such as the smoothed particle hydrodynamics (SPH) method and the material point method (MPM) [6]. The material point method is a new particle-type numerical method that combines the advantages of Lagrangian and Eulerian algorithms. It was proposed by [PERSON] and has been widely used to simulate the whole process of landslide failure [7; 8; 9; 10; 11; 12; 13]. Smoothed particle hydrodynamics is a numerical method proposed by [PERSON] and [PERSON] [14]. It describes a continuous fluid (or solid) as a group of interacting particles. Each material point has a variety of physical quantities, including mass and velocity. By solving the dynamic equation of the particle group and tracking the trajectory of each particle, the mechanical behavior of the whole system is obtained. The SPH method is a meshless method based on the Lagrangian description [15; 16; 17; 18]. It has been widely used in the simulation of landslide and debris flow disasters [19]. [PERSON] applied SPH to the elastoplastic relationship of rock and soil and then combined it with the strength reduction method to simulate the slope stability [20; 21]. Quantitative prediction of the dynamic evolution process of geological disasters is an important basis for solving the risk range of disasters and conducting risk assessments. This study takes a dump in Panzhihua as an example (Figure 1). Based on the MPM and SPH methods, the movement and accumulation of the dump slope after instability under different working conditions were simulated and predicted. The key parameters such as transportation speed, migration range, and accumulation thickness were calculated, and the displacement of the waste calculated by the two methods was comprehensively considered and analyzed. The final range of the potential threat of the dump was thereby realized. The research results are conducive to the risk assessment of the spoil slope.