高层剪力墙隔震结构动力特性简化计算方法

A simplified calculation method for dynamic characteristics of high-rise shear-wall isolated buildings

针对规则高层剪力墙隔震结构侧向变形特征,按楼层集中质量法建立的多质点模型进行模态分析,以振型有效质量为判断依据,确定了该类结构在采用振型分解反应谱法进行单轴向计算分析时可取前两阶振型。在考虑了隔震层转动影响前提下,基于所定义的线刚重比构建了该类结构前两阶自振周期、振型、振型阻尼比的简化计算方法及相应计算式,验证计算结果表明能够较好的反映出结构前两阶动力特性。当隔震层转动线刚重比较小时,若不计入其影响将导致二阶周期计算偏差较大。在此基础上给出了基于线刚重比的规则高层剪力墙结构隔震前后周期比的显式表达式,为高层隔震结构实用设计方法的研究提供了基础。

A simplified calculation method was proposed here for the lateral dynamic characteristics of high-rise shear-wall isolated buildings.When performing the uniaxial analysis,the building structure was modeled with the lumped mass method and the first two modes were analyzed with the response spectrum method based on the criterion of modal masses.Periods,modal shapes and damping ratios of the first two modes were calculated using simplified expressions based on the linear stiffness-gravity ratio considering rotation of base isolation.Numerical simulations showed that the simplified method can catch the dynamic characteristics of the first two modes.The explicit formulas for calculating period ratios of high-rise buildings without base isolation to those with base isolation were proposed.The results provided a foundation for the practical designs of high-rise shear-wall isolated buildings.