## 3 Characterization of Anchor Cable in FDEM
### Results
#### 4.2.3 Analysis of Entire Dynamic Evolution Process of the Landslide-Anchorage Structure System
When the seismic intensity is VII, the kinetic energy of the model starts to decrease after 15.97 s under the effect of the energy dissipation mechanism, during which the sliding body is squeezed and collides while moving, and the crack number further increases in a small amount and reaches the maximum value of 1647 at 18.2 s (Figure 13). The model finally stops moving at the end of the earthquake (\(t=22\) s) (Figure 12f). At the seismic intensities VIII and IX, the kinetic energy of the model starts to decrease at 12.48 s and 12.24 s, and the maximum values of the crack number are 1709 (Figure 13, 15.8 s) and 2456 (Figure 13, 16.5 s), respectively. When the seismic intensity is X, the kinetic energy of the model starts to decrease at 12.48 s, but due to the high intensity of the earthquake, the upper bedrock also collapses and is destroyed, and the kinetic energy peaks several times and reaches 0 at 22 s (Figure 14); the final crack number is 8321 (Figure 13, 19.36 s). Figure 12: Cont. The schematic diagram of the dynamic evolution of the landslide-anchorage structure system at all seismic intensities is shown in Figure 15. Among them, when the seismic intensities are VII, VIII, and IX, the anchor cables are intact and no landslide occurs; when the seismic intensity is X, the anchor cables fail in order, and overall failure occurs in the landslide-anchorage structural system. The above dynamic evolution process can be roughly divided into the following stages:  
1. Initial ground stress equilibrium stage (Figure 15a). 2. Rock mass near the free segment of the anchor cable failure stage. Prestresses are generated in the rock mass in the vicinity of the anchor cables after the anchor cables are prestressed, and with the application of seismic loads, the stress concentration enables this part of the rock mass to be more prone to fracture (Figure 15b, \(t\) = 5 s). This stage is observed at all seismic intensities. 3. Sliding surface penetration stage. This stage is the same as the dynamic evolution law of the unreinforced condition: take seismic intensity VII as an example, the toe of the inclined sliding surface is the first to tensile failure caused by the reciprocating motion  
Figure 14: Variation of kinetic energy of the model under different calculation conditions. Figure 12: Schematic diagram of the entire process of landslide dynamic evolution under unreinforced condition at different seismic intensities (similar process is omitted). Figure 13: Variation of crack number of the model under different calculation conditions. of the dynamic load at \(t=9.98\) s; then, shear failure occurs almost simultaneously at the horizontal structural plane, tensile failure occurs at the lower part of the trailing edge of the structural plane (Figure 15c, \(t=10\) s), and finally, the inclined sliding surface and the trailing edge of the structural plane continue to extend to penetration under the dual effects of gravity and seismic load at \(t=11\) s (Figure 15d). For other seismic intensities (Figure 16), the crack initiation time is 7.26 s for VIII, 6.24 s for IX, and 5.46 s for X, and the sliding surface penetration time is 9.31 s for VIII, 7.02 s for IX, and 5.91 s for X. It can be seen that the crack initiation time and penetration time of the structural plane are advanced with the increase in the seismic intensity. At the time of structural plane penetration, the crack number of the model at each seismic intensity is 129 (VII), 130 (VIII), 151 (IX), and 141 (X), showing an overall increasing trend and indicating that the number of secondary cracks at this stage is positively correlated with the seismic intensity. The kinetic energies of the model at the end of this stage are 9240 J (VII), 12,073 J (VIII), 21,837 J (IX) and 27,148 J (X), which is mainly related to the input seismic wave energy.