基于基础隔震理念的转体斜拉桥抗震性能研究

为研究基础隔震体系对转体斜拉桥抗震性能的影响，以新建福厦客运专线太城溪特大桥为工程背景，建立全桥动力模型，进行非线性时程分析。选取7组地震波与5组曲面摩擦摆支座基础隔震方案，对比分析基础隔震转体斜拉桥的抗震性能。结果表明：采用基础隔震体系后，转体斜拉桥的自振周期增大，整体刚度与地震响应显著降低；曲面摩擦摆支座对结构变形的影响较小，但会使内力大幅降低，可作为该转体斜拉桥基础隔震体系的隔震支座；采用基础隔震体系后，主墩墩底弯矩减小44.83%～55.82%,剪力减小40.3%～63.09%,塔梁固结处产生最大位移65.53 mm。

Seismic performance of rotational cable-stayed bridgesbased on the base isolation theory

To study the influence of a base isolation system on the seismic performance of rotational cable-stayed bridges, the Taichengxi Bridge on the newly-built Fuzhou-Xiamen passenger line was taken as the engineering background. A dynamic model of the entire bridge was established for a nonlinear time-history analysis. Seven seismic waves and five groups of base isolation schemes with curved surface friction pendulum bearings were selected to compare and analyze the seismic performance of the rotational cable-stayed bridge. The results showed that the natural period of the bridge increased, and the global stiffness and seismic response decreased evidently after adopting the base isolation system. Although the curved surface friction pendulum bearing had little influence on the structural deformation, it significantly reduced the internal force; therefore, it can be used as an isolation bearing in rotational cable-stayed bridges. With the adoption of the base isolation system, the bending moment at the bottom of the main pier could be reduced by 44.83%-55.82%, the shear force could be reduced by 40.3%-63.09%, and the maximum displacement in the rigid fixity zone of the tower and girder was 65.53 mm.