考虑震后残余位移的钢筋混凝土框架结构抗震性能评估

This project will focus on evaluating seismic performance of reinforced concrete frame structures accounting for post-earthquake residual displacement and the key scientific issues will be studied systematically. First, the effects of selecting and modifying ground motion records on the residual displacement results will be investigated thoroughly and suggestion for selecting and modifying ground motion records aiming at quantifying residual displacement rationally will be proposed based on large amount of nonlinear dynamic analysis results. Second, the accuracy of measuring maximum and residual displacement of structures via non-contact displacement measurement techniques will be physically investigated. Third, taking typical reinforced concrete frame structures as case studies, shaking table test will be conducted on scaled models. And refined numerical simulation both on protype and model structures of shaking table test will be performed. Comparison between shaking table test results and numerical simulation results will be conducted to evaluate the accuracy of residual displacement measurement and the sensitivity to model parameters. Furthermore, the feasible approach to quantify the maximum displacement of structures during earthquake from the measurable post-earthquake residual displacement will be put forward. Finally, rational post-earthquake performance evaluation indices accounting for residual displacement and the correlation between the indices and performance levels reflecting the damage states of structural and non-structural components will be further studied. And seismic fragility evaluation methodology of reinforced concrete frame structures will be proposed. This project can contribute to strengthening the theoretical foundation for rapid performance evaluation and efficient retrofitting of structures after damaging earthquake events.

本项目着眼于考虑震后残余位移进行钢筋混凝土框架结构的抗震性能评估，就涉及的关键科学问题进行深入系统的研究，主要包括：深入分析地震动记录的选择与调整对结构残余位移的影响并通过大量非线性动力分析结果提出以残余位移为主要分析指标时选择与调整地震动记录的建议；系统研究非接触式位移测量方式测量结构最大位移及残余位移的精准性；选择典型钢筋混凝土框架结构进行模型结构振动台试验，对振动台试验原型结构及模型结构进行精细的数值模拟，并与试验结果对比，分析残余位移预测的准确性和对模型参数的敏感性；建立由地震后可测的残余位移推算地震中结构最大位移的可行方法；在此基础上，研究合理的考虑残余位移的钢筋混凝土框架结构震后性能评估指标及其与结构构件、非结构构件损伤等性能水准的相关性，提出考虑震后残余位移的钢筋混凝土框架结构抗震易损性评估方法，从而为震后该类结构的性能快速评估和有效加固提供坚实的理论支撑。

本项目着眼于考虑震后残余位移进行钢筋混凝土框架结构的抗震性能评估，就涉及的关键科学问题进行了深入系统的研究，包括考虑残余位移指标的地震动强度指标及相应的地震动记录选择与调整方法，对基于谱匹配的方法进行了充分的研究，探讨了近场及远场地震动作用下钢筋混凝土框架结构最大层间位移角和最大残余层间位移角响应特征；提出了基于计算机视觉的非接触式位移测量方法，采用Matlab开发了应用程序，将其用以一钢筋混凝土框架-填充墙模型结构的振动台试验；通过理论分析和试验研究探讨了残余位移与最大层间位移的关系以及建立两者关系的可能性；在充分考虑填充墙平面内外相互作用、钢筋混凝土柱轴-剪-弯耦合效应、钢筋后期强度退化、P-delta效应等因素的基础上建立典型结构的精细有限元分析模型，采用弹塑性动力分析和增量动力分析评估结构抗震性能，进行地震易损性分析，建立了基于概率的考虑震后残余位移的结构地震易损性评价方式。.在研究过程中发现震后残余位移的离散性相对较大，影响震后残余位移的因素更多、更复杂，如地震动持时特性及其与地震动强度、频谱特性之间的耦合影响。基于此，较为系统地开展了地震动持时特性对包括震后残余位移的结构非线性响应的影响研究，在基于单一强度指标的条带法的基础上，通过引入向量型强度指标，提出了包含持时特性的进行地震易损性评价的条带-云图法，比较好地将地震动持时特性纳入了结构地震易损性评价。项目研究成果可以为更充分地进行结构抗震性能评价提供参考，也可以为发展既有低延性钢筋混凝土结构抗震加固、探索新型可恢复功能结构提供有效的支撑。