地震动输入能量谱的研究

Study on Input Energy Spectra of Earthquake Strong Motion

现有的抗震设计理论,大多是基于承载力或强度的设计方法,与其相应的反应谱理论最大的缺陷是无法反映地震动持时的影响,而以地震动能量作为设计参数时,就能弥补现有抗震理论的不足。本文按照反应谱理论的思路建立了线性单自由度体系的地震动输入能量谱。研究发现,输入能量谱对体系的阻尼比不敏感,地震波峰值速度与峰值加速度比值(V/A)和强震持时(Δt)对谱形的影响较大,体系的输入能量与地震波的峰值平方成正比,根据分析结果,本文提出了线性单自由度体系输入能量谱的简化计算方法,方法较为简便,计算结果偏安全。

Most of current methods in seismic design of structures require the provision of sufficient strength against anticipated seismic affects, the corresponding design response spectra can＇t reflect the effect of duration. Energy-based seismic design is known as an alternative design methodology. A parameter study is carried out with input energy spectra of linear SDOF system under earthquake ground excitation in this paper. It is found that the input energy spectra is not sensitive to the viscous damping ratio, the peak ground velocity to acceleration ratio（ V/ A ） and effective duration（ At ）of motions have much influence on the spectra. A simple analytical procedure is developed for calculating the input energy spectra of linear SDOF system, it can be employed in an energy-based seismic design procedure for determining the required energy dissipation capacity of a structural system.