Residual displacement spectrum is one of the most important means to predict the permanent deformation of structures after the earthquake, and various normalizations of residual displacements have generally been used for construction of the spectrum. However, the issue regarding the merits and drawbacks of each normalization has not yet been investigated thoroughly. A comparison between two normalizations that relate the residual displacements to the elastic and inelastic displacements is made in terms of the effect of ground motion and structural characteristics by means of the results of nonlinear time history analysis. The statistical results reveal that the residual-to-peak-inelastic displacement ratios have the advantages of small dispersion, samples without any outliers, and relatively symmetric distribution, which benefits from the strong correlation between residual and peak inelastic displacements. Moreover, the residual-to-peak-inelastic displacement ratios are almost independent of site conditions, significant duration, and natural periods. Consequently, the peak inelastic displacements are superior to the elastic ones as an intermediate step for residual displacements estimation, provided that the peak inelastic displacements are estimated with a low uncertainty. For providing alternatives to estimate residual displacement demands, the constant-strength residual displacement spectra are developed for both normalizations.

残余位移谱是预测地震后结构永久变形的最重要手段之一，残余位移的各种归一化方法通常用于构造该谱。但是，关于每个规范化的优缺点的问题尚未得到彻底研究。借助于非线性时程分析的结果，根据地震动的影响和结构特征，对将残余位移与弹性位移和非弹性位移相关联的两个归一化方法进行了比较。统计结果表明，残峰弹性位移比具有色散小，样本无异常值，分布相对对称的优点。这得益于残余位移和峰值非弹性位移之间的强相关性。此外，残余-峰值-非弹性位移比几乎与工地条件，有效工期和自然周期无关。因此，如果估算的峰值非弹性位移具有较低的不确定性，则峰值非弹性位移将优于弹性位移，这是残余位移估算的中间步骤。为了提供估计残余位移需求的替代方法，针对两种规格化开发了恒定强度残余位移谱。如果估计峰值非弹性位移的不确定性较低，则峰值非弹性位移优于弹性位移，这是剩余位移估计的中间步骤。为了提供估计残余位移需求的替代方法，针对两种规格化开发了恒定强度残余位移谱。如果估计峰值非弹性位移的不确定性较低，则峰值非弹性位移优于弹性位移，这是剩余位移估计的中间步骤。为了提供估计残余位移需求的替代方法，针对两种规格化开发了恒定强度残余位移谱。