地震作用下摩擦摆支座在桥梁结构中的动力特性分析

Analysis on dynamic characteristics of friction pendulum bearing in bridge structure under seismic action

以某高烈度区的预应力混凝土连续箱梁为研究对象,基于减隔震装置广泛应用于桥梁结构抗震设计中的工程背景,结合桥址处场地条件,引入摩擦摆减隔震支座对桥梁结构进行减隔震设计。通过非线性时程响应分析,对比研究了在摩擦摆减隔震支座的边界条件下和普通支座边界条件下的桥梁结构在设计地震荷载作用下的响应特性。分析结果表明:桥梁结构使用减隔震支座后的自振周期是使用普通支座的2.32倍,在设计地震荷载作用下,摩擦摆减隔震支座使桥梁结构达到全桥协同作用,大幅度降低了桥墩墩底弯矩和墩顶位移响应,减震耗能作用明显,优化了桥梁结构的抗震设计。

Taking a pre-stressed continuous box girder in a high intensity area as research object,based on the engineering background that isolation device is widely used in the anti-seismic design of bridge structure,the friction pendulum isolation bearing is introduced to carry out seismic isolation design of the bridge structure combining with the bridge site condition. Through the nonlinear time history response analysis,the response characteristics of the bridge structure under the designed seismic load of the boundary condition of the friction pendulum isolation bearing and the ordinary bearing are studied. The results show that the natural vibration period of bridge structure using isolation bearing is 2.32 times of the natural vibration period using ordinary bearings. Under the designed seismic load,the friction pendulum isolation bearing makes the bridge structure work together,and thus greatly reduces pier base bending moment and pier top displacement response of the bridge,and the damping energy dissipation effect is obvious.the seismic design of bridge structure is optimized.