## 5 Conclusions  
A novel force model for a hybrid isolation device is proposed in this paper. The theoretical analysis identifies the influence of active control on passive control within the hybrid isolation system. Based on the combination of active and passive control, a PID controller and a genetic algorithm are introduced to optimize the isolation capacity of the system. The following conclusions are drawn from the simulation and experimental results:  
* When the reaction force of the control system on the lower passive control is considered, the period of the hybrid isolation system increases under seismic excitation;
* The isolation efficiency of both the upper and lower layers of the system improves when the reaction force on the lower passive control is considered;
* The displacement response of the system amplifies when the reaction force on the lower passive control is considered. Overall, considering the reaction force on the lower passive control, the system's motion period increases, and displacement amplifies. However, the isolation performance is enhanced, effectively reducing the impact of seismic waves on the structure. By considering the reaction force from the upper layer to the lower layer, the proposed new hybrid isolation system can more accurately simulate the actual force conditions of structures. Traditional hybrid isolation systems often overlook this factor, while this study demonstrates that the reaction force significantly impacts the isolation performance. Accounting for this effect enhances the overall performance of the isolation system, particularly in responding to strong earthquakes. The proposed hybrid isolation system is not only applicable to bridges but also to buildings, precision instruments, cultural relics, and other structures. This indicates that the system has broad application prospects, especially in different engineering projects where it can effectively reduce earthquake damage and improve safety. With the application of intelligent optimization algorithms, this study offers a new direction for the development of future isolation technologies. Traditional passive isolation systems have limited performance under complex seismic conditions, while hybrid isolation systems incorporating active control can respond more flexibly and dynamically to seismic excitations, laying a foundation for the advancement of intelligent seismic technology. The research methods and conclusions presented in this paper provide a theoretical basis for designing more optimized isolation systems, especially offering insights into intelligent control and parameter optimization of such systems. Future research can further enhance the precision and adaptability of control algorithms, enabling isolation systems to better cope with complex and changing seismic environments. The proposed hybrid isolation system is not only limited to bridges but can also be applied to precision instruments and the protection of cultural heritage. Future studies can focus on adjusting system design and control strategies for different application scenarios, ensuring that optimal isolation performance is achieved under varying conditions. Conceptualization, N.L. and Y.S. ; methodology, N.L. ; software, N.L. and W.Z. ; validation, N.L., Z.Y., and W.Z. ; formal analysis, N.L. and Z.Z. ; investigation, Z.Y. ; resources, Y.S. ; data curation, N.L. ; writing--original draft preparation, N.L. ; writing--review and editing, Y.L. ; visualization, N.L. ; supervision, Z.Z. ; project administration, Y.S. ; funding acquisition, Y.S. All authors have read and agreed to the published version of the manuscript. This research was funded by the National Natural Science Foundation of China (Grant No. 52278536) and Natural Science Foundation of Sichuan Province (Grant No. 2024 NSFSC0428). Not applicable. Informed Consent Statement: Informed consent was obtained from all subjects involved in this study. The data that support the findings of this study are available from the corresponding author(s) upon reasonable request.