# Seismic Responses of GRS Walls with Secondary Reinforcements Subjected to Earthquake Loading
## 5 Conclusions  
A finite element investigation of GRS walls with/without secondary reinforcement under seismic loading was presented. The validated finite element procedure was based on the field GRS wall with secondary reinforcement and the large-scale shaking table tests by [PERSON] et al. (2015, 2016, 2018) [5, 13, 14], and [PERSON] et al. (2005) [27], and was utilized to carry out a parametric study of the seismic response of GRS walls with/without secondary reinforcement by assessing the relative lateral facing displacement, connection load, maximum reinforcement load, and acceleration amplification. Based on the study, the following can be concluded:  
1. Under earthquake loading, the relative lateral facing displacement was slightly lower in walls with secondary reinforcement than in walls without secondary reinforcement. However, no significant difference in relative lateral facing displacement was observed when the length or stiffness of the secondary reinforcement were increased. Under different wall heights, vertical spacings of the primary reinforcement layer, and PGAs, secondary reinforcement was found to have only a small influence on the relative lateral facing displacement.  
Figure 19: The effect of PGA on (**a**) the relative lateral displacement; (**b**) connection load; (**c**) maximum reinforcement load; (**d**) acceleration amplification of walls with and without secondary reinforcement.  
Increasing the length or stiffness of the secondary reinforcement can reduce the connection load and maximum reinforcement load in the primary reinforcement. The benefit of increasing the secondary reinforcement length is greater than the benefit of increasing its stiffness: compared to increasing the secondary reinforcement length, increasing its stiffness led to a smaller reduction in the connection load and maximum reinforcement load in the primary reinforcement. The secondary reinforcement effect for the performance of the walls is more effective for reducing the connection load and maximum reinforcement load than for reducing the relative lateral facing displacement.  
The effect of secondary reinforcement on decreasing the connection load and maximum reinforcement load is greater for higher walls, larger vertical spacings of the primary reinforcement layer, and smaller PGAs.  
The GRS walls with secondary reinforcement may help reduce the effect of the acceleration amplification, increasing the overall performance of GRS walls subjected to earthquake loadings.  
However, the number of critical factors investigated in this study is limited, and consequently, future studies should consider more critical factors to provide more insights on the seismic design of GRS walls with secondary reinforcement. This study indicates that installing secondary reinforcement between primary reinforcements can increase the performance of GRS walls under seismic conditions.  
Conceptualization: C.-H.L. and C.H.; validation: C.-H.L. and C.H.; formal analysis: C.-H.L. and C.H.; writing--original draft preparation: C.-H.L. and C.H.; writing--review and editing: C.-H.L. and C.H.; supervision: C.H.; resources: C.H.; visualization: C.-H.L.; funding acquisition: C.H.; data curation: C.-H.L. All authors have read and agreed to the published version of the manuscript.  
The research was funded by the Ministry of Science and Technology of Taiwan.  
The authors appreciate the Young Scholar Fellowship Program by the Ministry of Science and Technology, Taiwan: Grant 108-2636-E-006-003 & 109-2636-E-006-016. The research was, in part, supported by the Higher Education Sprout Project, Ministry of Education, Taiwan, Headquarters of University Advancement to the National Cheng Kung University.  
The authors declare no conflict of interest.