在强震或近场地震动作用下，传统隔震支座桥梁存在支座有残余位移和桥墩内力响应大的问题。受科学馆重力井曲面设施的启发，本文拟提出一种基于重力井曲面的变刚度摩擦摆支座。其曲面由内部的球面和外部的重力井曲面构成。首先，基于理论推导，揭示其水平剪切方向的恢复力模型。其次，设计并制作了一个足尺变刚度摩擦摆支座试件，并对其进行拟静力试验，以进一步探究其滞回特性和力学性能。摩擦材料采用抗压性能优越的改性超高分子量聚乙烯。最终，通过数值模拟，比较研究了重力井曲面摩擦摆支座和球形支座的动力特性。试验发现了变刚度双摩擦摆支座上下滑动面呈不对称滑动的现象。改性超高分子量聚乙烯摩擦材料可以满足支座对摩擦垫局部应力大的需求。此外，与普通球形双摩擦摆支座相比，重力井曲面摩擦摆支座能够大幅度减小地震动作用下的内力需求，且具有和小半径球面摩擦摆支座一样优越的自复位性能。

The traditional bridge with isolation bearings has the issue of residual displacement of the isolator and the response of internal pier force during the impact of an enormous earthquake or near-fault earthquake. This research suggests a variable-stiffness friction pendulum bearing based on a gravity-well surface, gaining inspiration from the facility for gravity-well surfaces in the Science Museum. Its surface is made up of a gravity-well surface outside and a sphere inside. First, the theoretical derivation-based restoring force model in the horizontal shear direction is revealed. Second, a footprint variable stiffness friction pendulum bearing specimen is designed, constructed, and put through a cyclic shear test to further examine its mechanical and hysteresis characteristics. The friction material was a modified ultra-high molecular weight polyethylene with better compression resistance. In the end, numerical simulations were used to compare the dynamic properties of the gravity well friction pendulum bearing with the spherical bearing. The sliding surface of the variable stiffness double friction pendulum bearing is asymmetrical. The high local stress on the friction pad can be accommodated by the modified ultra-high molecular weight polyethylene (UHMWPE) friction material. The gravity-well friction pendulum bearing can also significantly reduce the internal force demand under the action of ground motion when compared to the conventional spherical double friction pendulum bearing, and it has the same superior self-reset performance as the spherical friction pendulum bearing small radius.

广东省自然科学基金项目(面上项目，2022A1515011250),国家自然科学基金项目（面上项目，52178124）