## 6 Conclusions  
To study the seismic performance of rocking steel bridge piers, a high-precision FE computational model suitable for such structures was established for numerical simulation analysis. Based on the calculation results and theoretical analysis, the following conclusions can be drawn:  
(1) A comparison with the existing pseudo-static test results shows that the FE model used in this study achieves a high level of accuracy in simulating the horizontal load-displacement curve of rocking steel bridge piers;  
(2) Since the pier body is only used for energy dissipation peripherally and exhibits low plastic deformation, the hysteresis curves of concrete-filled rocking steel bridge piers and hollow rocking steel bridge piers are quite similar. Directly using hollow steel pier bodies improves the economic efficiency of the design;  
(3) Increasing the self-recovery index \(\lambda\) significantly enhances the energy dissipation capacity of the bridge pier, but care should be taken to prevent excessive residual displacement. With an increase in prestress ratio, both the bearing capacity and residual displacement of the pier increase. Significantly thicker base plate compared to the wall plate can significantly improve the pier's resistance to local instability. Making the radius of the base plate slightly larger than the cross-sectional radius of the pier avoids concave deformation of the base plate and increases the pier's bearing capacity by approximately 5%. An increase in axial compression ratio increases the additional moment, leading to early degradation of the bearing capacity;  
(4) Thickening base plates and adding longitudinal stiffeners can enhance the seismic performance of rocking steel bridge piers. Regardless of reinforcement within the range of 0.15 m or 0.3 m, reinforcing the thickness of the wall plate yields better results compared to additional longitudinal stiffeners.  
(5) When the wall plate is thickened as the diameter-to-thickness ratio reaches 0.048 within a range of 0.3 m, the maximum load-carrying capacity of the rock piers increases by 11.5%, energy dissipation decreases by 0.1%, initial stiffness increases by 18.9%, and the residual displacement decreases by 54.7%. Reinforcement at the bottom of the pier has little influence on energy dissipation capacity but can slow down the growth of residual displacement, increase the lateral stiffness of the pier, and have a positive effect on the seismic performance of the bridge. A greater reinforcement height is more effective in reducing residual displacement compared to thickening the wall plate.  
**Author Contributions:** Conceptualization, H.Z.; funding acquisition, H.Z.; investigation, H.Z. and C.N.; validation, C.N. and R.D.; writing--original draft preparation, H.Z. and C.N.; writing--review & editing, H.Z.; project administration, Z.T.; funding acquisition, H.Z. All authors have read and agreed to the published version of the manuscript.  
**Funding:** This research was funded by the General Program of National Natural Science Foundation of China, Grant No. 51878606 and China Postdoctoral Science Foundation, Grant No. 2023M730154.  
**Institutional Review Board Statement:** Not applicable.  
**Informed Consent Statement:** Not applicable.  
**Data Availability Statement:** Not applicable.  
**Conflicts of Interest:** The authors declare no conflict of interest.