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

该项目由地震修复和恢复计划（NSF 90- 23）的第二阶段支持。20世纪五六十年代在美国建造的钢筋混凝土框架结构通常包含与抗震性能差相关的非延性细节。实验研究了这些细节的行为。本项目探讨了提高这些结构抗震性能的策略。本研究的目的是：(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改造策略；(3)提供一种评估改造框架的方法；(4)利用该方法估计关键区域所需的强度和延性水平；(5)提出提高强度和延性的指导方针。将分析一系列非延性混凝土框架结构，并制定改造策略。分析模型将根据最近的实验结果进行校准。改造框架将被分析，改造策略将被评估。将制定临界区域强度和延展性适当水平的准则，并将提供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造技术，并将帮助实践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.