Evaluation of Existing Reinforced Concrete Columns

该项目与a 由W.霍姆斯 Rutherford Chekene（NSF Grant 第9120214号）， 第二阶段（第二年）计划 地震修复和重建 倡议（NSF 90-23）。 钢筋混凝土框架 在20世纪70年代之前建造的 损失的最大风险之一 由于崩溃， 强烈的地面震动 之一 这些结构的主要缺陷 比例不足， 列的细节。 的实例 不足之处包括 柱梁强度 轻型横向强度 钢筋和短搭接 接头 这项研究是为了进行一项 基于实验的研究 缺陷柱的行为， 发展计算方法 强度和变形能力 现有列供以下人员使用 结构工程师 的方法 将有助于（a）评价 现有结构和（B）用于 改造系统的设计， 旨在保护相对 现有的脆弱元素 结构 该研究包括详细的 审查现有数据， 钢筋混凝土性能 列，研究常见详细信息， 现有结构， 包含缺陷的列 代表那些发现在 现有建筑，数字的 建模和结果分析， 并制定一套实用的 一系列的规则来衡量 钢筋混凝土变形性能 在现有的结构中。 这项研究将在 研究人员/工程师联合在 加州大学 伯克利和卢瑟福·契肯。

This project, in collaboration witha companion project by W. Holmes of Rutherford & Chekene (NSF Grant No. 9120214), is supported under the Phase 2 (second year) program of the Seismic Repair and Rehabilitation Initiative (NSF 90-23). Reinforced concrete frames constructed prior to the 1970's pose one of the greatest hazards for loss of life due to collapse during strong ground shaking. One of the key deficiencies of such structures is inadequate proportioning and detailing of columns. Examples of deficiencies include insufficient column strength relative to beam strength, light transverse reinforcement, and short lap splices. This research is to conduct an experimentally based study of the behavior of deficient columns and to develop methods for calculating strength and deformability of existing columns for use by structural engineers. The methods will be useful (a) for evaluation of existing structures and (b) for design of retrofitting systems that are intended to protect relatively brittle elements of the existing structure. The research includes a detailed review of existing data on performance of reinforced concrete columns, study of common details in existing structures, experiments on columns containing deficiencies representative of those found in existing construction, numerical modeling and analyses of results, and development of a practical set of rules for gaging the strength and deformability of reinforced concrete columns in existing structures. The research will be carried out jointly by researchers/engineers at the University of California at Berkeley and at Rutherford Chekene.