耗能型自复位滑移铅芯橡胶支座隔震桥梁抗震性能研究

Study on Seismic Performance of Bridges with Energy Dissipation Self-centering Sliding-lead Rubber Bearings

为了提升梁式桥结构的抗震性能,提出了新型耗能型自复位滑移铅芯橡胶支座(SCSLRB),并基于形状记忆合金(SMA)滞回特性提出了耗能型自复位滑移铅芯橡胶支座隔震桥梁减隔震参数设计方法。首先,基于OpenSees平台分别建立耗能型滑移铅芯橡胶支座(EDSLRB)与形状记忆合金索的数值模型,分析了往复荷载作用下的滞回响应,并与试验结果进行了对比,验证了数值模型的准确性,进一步建立了耗能型自复位滑移铅芯橡胶支座数值模型。在此基础上,选取某3跨隔震连续梁桥,采用提出的减隔震参数设计方法,对耗能型自复位滑移铅芯橡胶支座参数进行了优化设计,并基于支座最优参数进一步研究了减隔震参数设计方法的适用性与耗能型自复位滑移铅芯橡胶支座隔震桥梁的抗震性能。结果表明:新型耗能型自复位滑移铅芯橡胶支座参数设计方法可有效得到隔震系统的最优参数;基于最优参数的新型耗能型自复位滑移铅芯橡胶支座隔震桥梁的自复位与耗能性能显著提升,能够实现主梁峰值位移、支座残余位移与桥墩地震剪力、弯矩的双重有效控制。其中,主梁峰值位移减幅达18.5%,支座残余位移显著减小,桥墩墩底剪力最大增幅仅为8.3%,支座耗能最大增幅达14.8%。研究结果可为近场地震作用下梁式桥抗震韧性提升提供有益参考。

To improve the seismic performance of girder bridges,this study proposes a novel energy dissipation self-centering sliding-lead rubber bearing(SCSLRB).A parameter design method for bridges with energy dissipation SCSLRBs is further suggested based on the hysteretic properties of the shape memory alloy(SMA).First,the numerical models of the energy dissipation sliding-lead rubber bearing(EDSLRB)and the SMA cables are created based on the OpenSees Software,the hysteretic responses of which are analyzed under cyclic loadings and are compared with the test results to verify the accuracy of the numerical models.The numerical model of the energy dissipation SCSLRB is further achieved.Based on the verified numerical model,by selecting a seismically isolated bridge,the optimal design of the parameters of the energy dissipation SCSLRB system is conducted based on the proposed parameter design method.The applicability of the proposed design method and the seismic performance of the bridge isolated by energy dissipation SCSLRBs are further investigated and discussed based on the optimum parameters.Results show that the optimum parameters of the energy dissipation SCSLRB system are achieved by the proposed parameter design method.The seismic performance of the energy dissipation SCSLRB system for response mitigation of bridges under near-fault earthquakes is effectively improved using the optimum parameters.The displacement of the bridge deck,the residual deformation of the SCSLRB,base shear and bending moment of the piers are dual effectively mitigated.In particular,the girder displacement is reduced by 18.5%,the residual deformation is significantly reduced,the base force of the piers is only increased by 8.3%,the energy dissipation of the novel bearing is improved by 14.8%.Results can provide a reliable basis for resilience improvement of girder bridges under near-fault earthquakes.