## 7 Conclusions  
The Dabenliu quarry slope in the Jinping I Hydropower Station is a typical high-steep bedding slope. We initially analyzed the failure modes of the slope. Then, the deformation failure process of the slope after excavation and under earthquake action was simulated using DDA, and the reinforcement design scheme was adjusted accordingly. Finally, our simulation results were verified via a comparison with the monitoring data of the slope. The main conclusions that can be drawn from the present study are as follows:  
(1) After the slope is excavated, the middle and upper strata may slip along the interlayers, while the lower part may slip and crack along the joints or small faults and then gradually extrude outward. This is a typical buckling failure mode characterized by upper-slipping followed with lower-buckling. This slope deformation failure process was vividly simulated via DDA simulation. The deformation failure mechanism can be attributed to two reasons: a special mechanical structure in rock strata and an angle relationship favorable for deformation between the strata and the excavated slope.  
(2) A method for setting a viscous boundary in the calculation of dynamic deformation under seismic loading and an algorithm for modeling pre-stressed cable were developed. The effect of reinforcing the slope under seismic loading was further discussed. Under the action of a magnitude 8 earthquake, the anchored slope may be instable. Based on the distribution of the simulated internal force of the anchor cables, the reinforcement scheme was adjusted to strengthen the support of the middle and lower parts of the slope and reduce the length and pre-stress of the anchor cables in the upper part. The adjusted reinforcement scheme can maintain the stability of the slope under the action of a magnitude 7 earthquake, but the slope may fail without evident collapse under the action of a magnitude 8 earthquake.  
(3) Through a comparison with the monitoring data of the surface, shallow deformation, and anchoring force, it was found that after excavation completion, the deformation of the slope shows a tendency towards a convergence state under the support of the anchor cables, and this is consistent with the results of the DDA simulation. Therefore, the Dabenliu quarry slope is stable and safe. This study also proved that the proposed reinforcement scheme is effective and that the DDA method is a powerful tool for simulating the complex process of rock mass deformation failure under different loading conditions.  
Conceptualization, F.X. and W.-H.H.; methodology, Q.-H.Z.; software, W.-H.H.; validation, W.-H.H., F.X. and Q.-H.Z.; formal analysis, F.X.; investigation, W.-H.H.; resources, F.X.; data curation, Q.-H.Z.; writing--original draft preparation, W.-H.H.; writing--review and editing, F.X.; visualization, W.-H.H.; supervision, W.-H.H.; project administration, Q.-H.Z.; funding acquisition, F.X. All authors have read and agreed to the published version of the manuscript.  
This research was funded by the General Program of the National Natural Science Foundation of China (Grant number 52079129, 52209148).  
Not applicable.  
The authors declare no conflict of interest.