基于不同归一化参数的单自由度体系残余位移比离散性研究

胡进军 刘巴黎

摘要：结构弹塑性特征的差异会引起残余位移较大的离散性，使得强震下结构残余位移难以准确预测.为准确评估和预测震后结构残余位移，实现精细化的抗震设计和评估，有必要研究结构残余位移的离散性.鉴于此，基于大量分类地震动记录，选用不同的归一化参数分别定义残余位移比，通过非线性时程分析建立单自由度体系残余位移比谱，研究弹塑性特征参数（延性系数和强度折減系数）以及场地条件对残余位移比离散性的影响，建立了残余位移比变异系数谱的拟合公式.结果表明：残余位移与弹塑性谱位移的相关性比与弹性谱位移更好；结构残余位移比离散性受场地类别的影响较小；残余位移比变异系数谱分别随延性系数和强度折减系数的增大而增大；选择弹塑性谱位移作为归一化参数可以减小结构残余位移比离散性.

关键词：残余位移；归一化参数；相关性；离散性；结构弹塑性特征参数

中图分类号：P315.92文献标志码：A

基金项目：国家自然科学基金重点项目（U1939210），National Natural Science Foundation of China（U1939210）

Study on Variability of Residual Displacement Ratios Based on Different Normalized Parameters for SDOF Systems

HU Jinjun1，2，LIU Bali1，2

（1. Institute of Engineering Mechanics，China Earthquake Administration，Harbin 150080，China；2. Key Laboratory of Earthquake Engineering and Engineering Vibration，China Earthquake Administration，Harbin 150080，China）

Abstract：The elastic-plastic characteristics of the structure will lead to large dispersion of the residual dis-placements，which makes it difficult to predict the residual displacements accurately under strong earthquake excita-tions. In order to accurately evaluate and predict the residual displacements of the structure and realize the refined a-seismic design，it is necessary to investigate the dispersion of the residual displacement of structures. In the light of this，based on a large number of classified ground motions，different normalized parameters are used to define the residual displacement ratio in this paper. The residual displacement ratios spectra of single degree of freedom（SDOF）systems are constructed by means of nonlinear response time-history analyses. The results are statistically organized to evaluate the influence of the following parameters： elastic-plastic characteristic parameters（ductility factor and strength reduction factor）and site condition. A simplified expression is presented to estimate the variation coefficient spectra of residual displacement ratios. It is concluded that the correlation between residual displacements and inelas-tic spectral displacements is better than that between residual displacements and elastic spectral displacements. The dispersion of the residual displacements is less affected by the site conditions. The variation coefficient spectra of residual displacement ratios increase with the increase of elastic-plastic characteristic parameters. It is suggested to select the inelastic spectral displacement as the normalized parameter，which can reduce the dispersion of the residual displacement ratios.

Key words：residual displacement；normalized parameter；correlation；dispersion；elastic-plastic characteristic parameter of structure

结构在强震作用下进入非线性阶段会产生不可恢复的残余位移[1]，结構残余位移是抗震性能评估和地震损失评估的重要参数[2-5]. FEMA P-58[6]将残余位移作为决定结构震后修复或拆除的重要指标.《建筑抗震韧性评价标准》（GB/T 38591—2020）[7]中建筑的抗震韧性由弹塑性时程分析的层残余变形结合其限值确定，并给出了部分结构形式层残余位移角的限值.

结构自……