考虑土-结构相互作用和主余震序列的自定心混凝土框架的抗震性能和抗震设计

To reduce the post-earthquake residual deformation and damage of reinforced concrete frames, a novel self-centering (SC) concrete frame has previously been proposed by the applicant, the SC frames were investigated through the tests on beam-column connections and overall frames, the development of seismic design procedure and performance evaluation of structures. However, many questions still remain unanswered with regard to real applications of this novel structural system. Through an in-depth analytical and experimental study, this project aims to study the seismic performance and design of SC concrete frames considering soil-structure interaction (SSI) and mainshock-aftershock sequences. The contents of the project are as follows: 1) based on the proposed analysis model of soil-structure system, nonlinear response spectrum of the SC structural system considering SSI effects is studied; 2) through nonlinear time-history analysis and shake-table experiment, the influence of SSI on the seismic behavior of SC concrete frames is investigated, and seismic design method of SC concrete frames considering SSI is established; 3) study the damage evolution of SC concrete frames under mainshock-aftershock sequences, and develop the methodology to integrate aftershock seismic hazard into the seismic design of SC concrete frames within the performance-based earthquake engineering (PBEE) framework.

为减少钢筋混凝土框架的震后残余变形和损伤，申请人于前期提出了一种新型的自定心混凝土框架，并从梁柱节点和整体框架的试验、抗震设计和性能评估等方面，进行了研究。然而，如何将这种新型的抗震结构体系应用到实际工程中，仍有许多问题亟待解决。本项目拟通过系统的理论分析和试验研究，对考虑土-结构相互作用（Soil-structure interaction，SSI）和主余震序列的自定心混凝土框架的抗震性能和设计方法进行研究。研究内容包括：1）基于提出的土-结构分析模型，研究考虑SSI效应的自定心结构系统的非线性反应谱；2）通过非线性动力时程分析和振动台试验，研究SSI效应对自定心混凝土框架抗震性能的影响，提出考虑SSI效应的自定心框架的抗震设计方法；3）研究自定心混凝土框架在主余震作用下的损伤演化，并在基于性能的地震工程框架内，建立在自定心框架的抗震设计中考虑余震危险性的方法。

本课题以自定心抗震结构为研究对象，对其在考虑SSI效应和主余震作用时的抗震性能和设计方法进行研究。开展的主要工作包括：1）基于自定心单自由度系统，建立了考虑SSI效应的自定心结构的非线性谱模型，研究了土体特性参数和结构特征参数对非线性位移比的影响规律；2）建立了考虑SSI效应的自定心混凝土框架的有限元分析模型，采用非线性动力时程分析方法，对比了考虑和未考虑SSI效应的自定心混凝土框架的抗震性能；3）采用概率地震需求分析方法，研究了余震对自定心混凝土框架抗震性能的影响规律，建立了自定心混凝土框架的概率地震需求模型和地震需求（最大层间位移角和残余层间位移角）的危险性曲线；4）建立了自定心单自由度结构考虑SSI效应的抗震设计方法，并基于动力时程分析方法验证了设计方法的正确性。5）采用自定心混凝土框架对某四层传统钢筋混凝土框架结构进行了抗震加固，实现了自定心混凝土框架结构的工程应用。