###### Abstract  
(1) Background: In most cases, passive isolation control methods are commonly used for the seismic isolation design in bridge engineering. However, passive seismic isolation devices, due to their non-adjustable performance parameters, struggle to achieve effective seismic isolation across a wide frequency range of 0 Hz to 20 Hz in response to random and varying seismic loads. (2) Methods: The sensitivity of the design parameters of the seismic isolation bearing was analyzed using the optimization center gradient method, and an improved genetic algorithm was employed to quickly optimize and obtain the optimal design parameters. (3) Results: The effectiveness of the three-dimensional seismic isolation bearing was validated through experiments. (4) Conclusions: The multi-factor sensitivity analysis approach used in this study for designing novel isolation bearings is applicable not only to seismic design in bridges but also serves as a reference for parameter design in isolation bearings requiring medium to high precision in seismic performance. three-dimensional seismic isolation bearing; bridge engineering; sensitivity of the design parameters; improved genetic algorithm; good seismic isolation effect +
Footnote †: journal: Medical  
experiments. [PERSON] et al. [10] established a new seismic damping system using viscous dampers for cross-sea cable-stayed bridges in deep water environments and designed experiments to verify the reliability of the seismic isolation effect. So far, seismic isolation devices have played an important role in enhancing wind and earthquake resistance in bridge structures. In most cases, passive isolation control methods are commonly used for the seismic isolation design of structures [11; 12; 13]. From the above research, it can be seen that the optimal isolation effect of isolation devices is closely related to the mass, geometric dimensions, dynamic characteristics, site environment, and external load characteristics of the isolated object [14; 15; 16; 17]. To achieve the best isolation effect for different isolated objects and seismic loads, it is necessary to design isolation devices with varying performance parameters. Therefore, for passive seismic isolation devices, due to their non-adjustable performance parameters, it is challenging to achieve a good seismic isolation effect for structures under random and variable seismic loads in the wide frequency range of 0 Hz to 20 Hz [18; 19; 20]. In order to identify the dynamic parameters of passive seismic isolation devices, computational intelligence meta-heuristic algorithms are commonly adopted [21; 22]. [PERSON] et al. [23] presented a brief literature review related to various applications of optimization as a tool for seismic protection, specifically arguing that meta-heuristic techniques should be combined with appropriate formulations of seismic protection optimization problems. [PERSON] et al. [24] presented an overview of seismic design optimization for structures, focusing on common solution methods, types of optimization problems, and goals of optimization while also highlighting directions for future research. Based on the literature review, a fuzzy optimization model for a new three-dimensional seismic isolation bearing used in bridge engineering was established, and the corresponding relationship between optimal seismic isolation performance and the coupling effects of design parameters was studied. Firstly, the shape and parameters to be optimized for the three-dimensional seismic isolation bearing were determined through a topology optimization method. Subsequently, a quantitative function was established with the optimization objective of minimizing the acceleration transfer rate. Then, the sensitivity of the design parameters of the seismic isolation bearing was analyzed using the optimization center gradient method, and an improved genetic algorithm was employed to quickly optimize and obtain the optimal design parameters.