FPBs combine the dual effects of pendulum action and friction energy dissipation. When an earthquake occurs, the bearings swing along the spherical sliding surface to extend the natural vibration period of the structure, avoiding the resonance frequency band of seismic waves. Meanwhile, the friction between the sliding surfaces dissipates most of the seismic energy. The synergy of these two mechanisms can reduce the seismic force borne by the superstructure by 3–5 times, significantly enhancing the disaster resistance of buildings and bridges in high-intensity seismic zones.
Unlike traditional sliding bearings that tend to suffer permanent displacement after an earthquake, FPBs can automatically return to their initial position relying on the geometric characteristics of the spherical curved surface and gravitational action, with no residual deformation. This feature allows buildings and bridges to resume service with only simple inspections, without large-scale resetting and maintenance, thus greatly reducing post-earthquake repair costs and time.
The spherical sliding surface of FPBs enables horizontal displacement in any direction, effectively withstanding multi-directional seismic actions such as P-waves and S-waves, and adapting to the impact of irregular seismic waves. Compared with unidirectional isolation bearings, FPBs are more suitable for engineering scenarios requiring multi-directional isolation, such as long-span bridges and special-shaped buildings.
FPBs feature a simple and stable stress structure, with vertical load-bearing capacity ranging from 100kN to 100,000kN, which can meet the load requirements of heavy-duty structures like super high-rise buildings, long-span bridges, nuclear power plants, and large-scale stadiums. Meanwhile, while bearing large vertical loads, the bearings still maintain excellent horizontal displacement capacity (maximum displacement up to ±500mm).
The core sliding components of FPBs are made of wear-resistant and corrosion-resistant materials (such as stainless steel plates, polytetrafluoroethylene plates, and high-performance composite materials). They can operate stably in an extreme temperature range of -40℃ to 80℃, and are resistant to acid, alkali, and aging. Under normal service conditions, the designed service life of the bearings can reach 60–100 years, far exceeding that of traditional rubber bearings (20–30 years), with extremely low long-term maintenance costs.
FPBs adopt a modular design, which allows direct connection with embedded parts without complex on-site commissioning, ensuring high construction efficiency. In addition, their excellent isolation effect can significantly optimize the seismic reinforcement design of the superstructure, reducing the overall project cost by about 10%–30%. Moreover, the bearing components support individual replacement, facilitating later maintenance and upgrading.