三重摩擦摆隔震梁桥的一种简化设计方法

摘要

Triple friction pendulum is a kind adaptive passive isolation bearing which is being used increasingly in practical engineering.Various independent friction pendulums will be formed corresponding to different motion status,which ensures that the bearing could satisfy seismic demands of different fortification levels.In order to develop efficient algorithm,the formulations of effective stiffness,damping ratio and period of different moving stages were derived based on simplified kinetic assumptions and design parameters of TFP.A simplified calculation approach was established to simulate regular bridge structure isolated by this kind of TFP bearings.An isolation design scenario of a long-span continuous girder-arch bridge was simplified to an equivalent SDOF damped mass-spring model.The equivalent mechanical parameters of the model were calculated.The design displacement of bearings as well as the horizontal seismic forces of the model could be obtained.Consequently,seismic design of the bridge was executed.Comparative study between the simplified model and the finite element simulation validated the soundness of the authors' method.%三重摩擦摆(TFP)系统是具有自适应特性的被动隔震支座,在不同运动状态下可形成多个相互独立的摩擦摆,能够适应不同设防水准的地震需求,因而得到日益广泛的工程应用.为了给出简单实用的计算方法,作者对TFP设计参数进行简化,根据运动状态假定推导了不同运动阶段的等效刚度、等效阻尼以及等效周期等基本参数的计算公式.给出了采用此类TFP隔震规则梁桥的简化设计方法,并将TFP隔震连续梁拱桥简化为等效单自由度模型,计算了等效模型的等效力学参数,得到了简化模型的支座设计位移和墩身地震力,并对简化模型进行了抗震设计.简化算法和有限元模型的计算结果比较,表明了本文简化模型和算法的合理性.