以简化成单自由度(SDOF)体系结构在地震作用下的输入能量为基础,研究地震输入能量和结构最大变形之间的关系。对于刚度退化SDOF体系,引入表征能量和变形间关系的等效速度比拳数,以3种场地下的214条近断层地震记录为输入,采用非线性时程计算和统计分析方法,提取累积输入能量、瞬时输入能量和非弹性变形间关系的分布特征,提出了不同场地下等效速度比的分段线性化函数,并用多自由度(MDOF)桥墩算例的时程计算结果进行了对比分析。结果表明:所建议的简化计算方法是有效的,可用于基于能量的桥梁结构抗震设计与评估。
Based on input energy of structure under seismic effect which is simplified as single degree of freedom (SDOF) systems, the special relationship between input energy and structural maximum deformation was studied. For stiffness degradation SDOF system, relation of cumulative input energy, momentary input energy and inelastic deformation was studied by introduction of the parameter of equivalent velocity ratio. Using inelastic time history analysis of SDOF system excited by 214 near-fault earthquake records from 3 kinds of soil sites, the distribution characteristic of the above relation was extracted by statistical analysis. The piecewise linear functions of equivalent velocity ratios under different sites were presented. Calculated results of time history of multiple degrees of freedom (MDOF) bridge pier were analyzed. Results show that the proposed simplified calculation method which can be used for energy based seismic design and assessment of bridge structures is effective.