Evaluation of Seismic Retrofit Strategies for Non-ductile Concrete Frame Structures

该项目得到了地震修复和恢复倡议(NSF 90-23)第二阶段的支持。在20世纪50年代的S和60年代的S期间，美国建造的钢筋混凝土框架结构往往含有与抗震性能差相关的非延性细节。对这些细节的行为进行了实验研究。本项目致力于改善这些结构的抗震性能的策略。研究的目的是：(1)概述非延性混凝土框架结构的改造策略，(2)研究基于提高关键框架细节和区域的强度和延性的加固策略，(3)提供一种评估改装框架的方法，(4)使用该方法估计关键区域所需的强度和延性水平，以及(5)建议改善强度和延性的准则。将对一系列非延性混凝土框架结构进行分析，并制定加固策略。分析模型将根据最近的实验结果进行校准。将对改造框架进行分析，并对改造战略进行评估。将制定关键区域强度和延展性的适当水平的指导方针，并将提供一种评估改造战略的方法。指南和方法将帮助其他研究人员开发改装技术，并将协助执业工程师对现有结构进行改造。该项目将包括与其他研究人员和建筑抗震设计实践工程师的互动。

This project is supported under Phase 2 of the Seismic Repair and Rehabilitation Initiative (NSF 90- 23). Reinforced concrete frame structures constructed in the U.S. during the 1950's and 1960's often include non-ductile details associated with poor seismic performance. The behavior of these details has been studied experimentally. This project addresses strategies for improving the seismic performance of these structures. The objectives of the research are: (1) to outline strategies for retrofit of non-ductile concrete frame structures, (2) to investigate retrofit strategies based on improving the strength and ductility of critical frame details and regions, (3) to provide a methodology for evaluating retrofit frames, (4) to use the methodology to estimate the levels of strength and ductility needed for critical regions, and (5) to recommend guidelines for strength and ductility improvement. A series of non-ductile concrete frame structures will be analyzed and retrofit strategies will be formulated. Analytical models will be calibrated with recent experimental results. Retrofit frames will be analyzed and retrofit strategies will be evaluated. Guidelines for appropriate levels of critical region strength and ductility will be developed, and a methodology for assessing retrofit strategies will be provided. The guidelines and methodology will assist other researchers in developing retrofit techniques, and will assist practicing engineers in the retrofit of existing structures. The project will include interactions with other researchers and practicing engineers in the seismic design of buildings.