For earthquake-resistant design, structural degradation is considered using traditional strength modification factors, which are obtained via the ratio of the nonlinear seismic response of degrading and non-degrading structural single-degree-of-freedom (SDOF) systems. In this paper, with the aim to avoid the nonlinear seismic response to compute strength modification factors, a methodology based on probabilistic seismic hazard analyses (PSHAs), is proposed in order to obtain strength modification factors of design spectra which consider structural degradation through the spectral-shape intensity measure $I_{N_{\mathrm{p}}}$. PSHAs using $I_{N_{\mathrm{p}}}$ to account for structural degradation and Sa(T₁), which represents the spectral acceleration associated with the fundamental period and does not consider such degradation, are performed. The ratio of the uniform hazard spectra in terms of $I_{N_{\mathrm{p}}}$ and Sa(T₁), which represent the response of degrading and non-degrading systems, provides new strength modification factors without the need to develop nonlinear time history analysis. A mathematical expression is fitted to the ratios that correspond to systems located in different soil types. The expression is validated by comparing the results with those derived from nonlinear time history analyses of structural systems.

中文翻译：

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考虑结构退化的抗震设计谱的基于强度的强度修正因子

对于抗震设计，考虑使用传统强度修正因子来考虑结构退化，这些因子是通过退化和非退化结构单自由度（SDOF）系统的非线性地震响应之比得出的。为了避免非线性地震响应来计算强度修正因子，提出了一种基于概率地震危险性分析（PSHAs）的方法，以获得考虑结构退化的设计光谱的强度修正因子。形强度测量 ${\mathrm{一世}}_{{ñ}_{\mathrm{p}}}$。PSHA使用 ${\mathrm{一世}}_{{ñ}_{\mathrm{p}}}$考虑到结构的退化，执行Sa（T ₁），它表示与基本周期相关的频谱加速度，并且不考虑这种退化。均匀危险谱的比率以 ${\mathrm{一世}}_{{ñ}_{\mathrm{p}}}$Sa（T ₁）和Sa（T ₁）分别代表退化和非退化系统的响应，提供了新的强度修正因子，而无需进行非线性时程分析。对应于位于不同土壤类型中的系统的比率，可以使用数学表达式。通过将结果与从结构系统的非线性时程分析中得出的结果进行比较，可以验证表达式的有效性。