长周期隔震结构基于反应谱理论的地震响应预测研究

The seismic response prediction of long-period seismic isolated structures based on response spectrum theory

在长周期基础隔震结构的地震响应计算或设计的某些阶段(如初步设计阶段或设计完成后的评估阶段),有必要建立一种地震响应实用计算方法,通过简单计算即能体现地震动长周期分量作用,提高隔震结构的地震安全性。通过选用合适的强震记录建立适合一定阻尼比和周期范围的、相应于规范设防烈度的相对位移、相对速度和绝对加速度反应谱,给出实用算式及地震动位移峰值和速度峰值;基于周期等效等准则,建立基础隔震结构的双质点系简化计算模型,推导简化计算模型参数、动力特性及地震响应的简化算式。建立基础隔震结构地震响应预测方法。利用建立的反应谱实用算式及两质点系计算模型的参数和动力特性的简化算式,可快速预测大阻尼比、长周期隔震结构地震响应。

Method for calculation of seismic structural response is necessary for the design of base-isolated structures. Reduction of earthquake hazard of isolated structures can be improved by taking account of long-period earthquake effects. Relative displacement spectrum, relative velocity spectrum and absolute acceleration spectrum with appropriate damping ratio and natural period were constructed according to the code fortification intensity through selecting suitable strong motion records. Relevant spectral calculation formulas and peak value of ground motion were provided through statistical calculation. Double-mass simplified calculation model for base-isolated structures was set up based on the simplification principle of equivalent natural period. Simplified calculation formulas for the double-mass model parameters as well as the dynamic characteristics and seismic response were derived, and seismic response prediction method was proposed.