## 5 Conclusions  
A low cycle pseudo-static test on different types of piles for IAJBs was carried out to investigate their different mechanical behaviors in terms of damage mode, horizontal deformation and bearing capacity, strain and bending moment distribution. Based on the analyses of the experimental results, the seismic design criteria of three-stage seismic fortification and five damage levels for the concrete piles of IAJBs were put forward and the following conclusions are drawn.  
1. With the increase of reinforcement ratio, buried pile depth and prestressing level, the pile damage depth shifted to a deeper depth of the pile and also showed a better pile-soil interaction. Moreover, the rectangular pile had a larger soil-pile interaction than the circular pile. The H-shaped steel pile showed a better elastic-plastic deformation capacity, ductility and energy dissipation capacity as compared to the concrete pile.
2. The inflection point of pile deformations shifted deeper with the increase of reinforcement ratio, buried pile depth and prestressing level, which increased the effective length and horizontal deformation capacity of the pile. The deformation inflection point of the PHC pipe piles was at a deeper buried depth as compared to the reinforced concrete piles.
3. The crack resistance of concrete piles was improved with the increase of reinforcement ratio and prestressing level, which is advantageous for the crack resistance design of the reinforced concrete, prestressed and PHC pipe pile foundations in IAJBs. The effect of the larger reinforcement ratio and prestressing level on the concrete crushing was insignificant.
4. The hysteresis area of the H-shaped steel pile was larger than the concrete pile which demonstrated a greater energy dissipation capacity. Moreover, the pile foundation with larger buried depth, prestressing level and cross-section had a better energy dissipation capacity.
5. The pile with larger bearing ratio can sustain more bearing capacity whereas the surrounding soil may be subject to larger loads.
6. The seismic design criteria of three-stage seismic fortification and five damage levels of the concrete piles can be used as a design reference for IAJBs. Currently, considering that the pile foundations are susceptible to earthquake damage, studies on the restoration and reinforcement of pile foundations do not go into sufficient detail following earthquake events.  
All authors substantially contributed to this work. [PERSON] designed and fabricated the pile model. [PERSON] and [PERSON] designed the experiment. [PERSON] and [PERSON] performed the experiments and analysis. [PERSON] wrote the paper. [PERSON], [PERSON] and [PERSON] revised and finalized the paper. All authors helped with the writing of the paper. All authors have read and agreed to the published version of the manuscript.  
Figure 20: Seismic design criteria of pile foundation.  
**Funding:** This research was funded by the National Natural Science Foundation of China with Grant Numbers 51578161, and by the Fuzhou Technology Bureau with Grant Number 2018-G-63.  
**Acknowledgments:** This project was supported by National Natural Science Foundation of China with Grant Numbers 51578161, and by the Fuzhou Technology Bureau with Grant Number 2018-G-63. The writers also thank the Sustainable and Innovative Bridge Engineering Research Center of Fujian Province University.  
**Conflicts of Interest:** The authors declare no conflict of interest.