结构抗震分析的耐震时程方法

The endurance time method for seismic response analyses of building structures

耐震时程法是一种新的生成地震加速度时程的方法,其典型表征在于随着持续时间的增加,地震动强度逐渐增大,且任一时程的反应谱曲线与目标反应谱吻合。采用非线性最小二乘函数合成了基于我国抗震设计规范反应谱的耐震时程曲线,并研究了该方法的精度和可靠性。以耐震时程曲线和7条地震动作为输入,对比分析了弹塑性SDOF体系和7层钢筋混凝土框架结构的响应特征。结果表明,耐震时程分析结果处于7条地震动增量动力分析结果的包络线之内,其结果宏观上表现为多个地震动输入结果的平均值;耐震时程法能有效地预测结构的抗震效应且计算效率高。耐震时程法将为不同类型结构的地震响应分析与预测,结构抗震动力试验输入,结构的抗震性能评估等提供一种新的分析手段。

Endurance time method （ETM） is a new procedure of simulating earthquake accelerations, which has the properties that the intensity of the ground motion linearly increases with the time of the time-history and the re- sponse spectra of any time interval fit with the corresponding target spectra. Nonlinear least-squares function is used to generate the accelerograms which are based on the response spectra of Chinese seismic design code. In addition, the accuracy and reliability of the procedure are discussed. Comparison studies of inelastic SDOF systems and a 7- story reinforced concrete frame structure subjected to endurance time accelerogram and 7 ground motions, have been performed to acquire the response characteristics. The analytical results indicate the responses of endurance time analyses are usually between envelopes of incremental dynamic analyses of seven motions, and present the av- erage values of ground motions results in macro view. Endurance time method has the potential for predicting the seismic response of structures with a high computing efficiency. Furthermore, Endurance time method could provide an alternative tool for determining the dynamic input of seismic experiments and evaluating the structural perform- ance.