Earthquake-Resistant RC Frames with High-Strength Concrete and Yielding Columns

本项目将研究两个参数对框架响应的影响：(a)高强混凝土和(b)柱屈服。目前缺乏支持高强混凝土和柱屈服影响的现有假设的物理数据。虽然这两个参数属于不同的类别（一个是材料属性，另一个是设计选项），但在这两种情况下，缺乏一般的理论理解，会导致钢筋混凝土建筑抗震设计中收缩选择的效果相同。提出的10个钢筋柱梁组合试件的设计是为了捕捉钢筋混凝土框架主要在框架平面上响应地震激励的基本特征。尺寸、材料和加载速率的选择将在实验设备的限制范围内将尺度效应降到最低。试验变量为(1)混凝土强度，名义上为5,000和10,000 psi；(2)柱的轴向单位应力，850和1700 psi或“平衡荷载”的一半，(3)屈服位置，在柱或在梁。本研究期望提供：(1)关于测试变量影响的直接结论；(2)利用调查数据对现有的迟滞算法进行测试；(3)如有必要，开发新的迟滞算法，以反映观测到的柱、梁和节点的变形；(4)确定测试或开发的迟滞算法的可信适用范围；(5)混凝土强度和柱屈服对框架响应影响的参数化研究，作为开发简单设计程序的基础；(6)确定适用范围的设计程序建议。＊＊＊

9320150 Sozen This project will investigate the effect on frame response of two parameters: (a) high-strength concrete and (b) column yielding. Physical data to support the currently existing hypotheses about the effects of high strength concrete and column yielding are lacking. Although the two parameters are of different classes (one a material property and the other a design option), lack of general theoretical understanding in either case leads to the same effect of constricting choices in earthquake-resistant design of reinforced concrete buildings. The proposed ten test specimens of reinforced column-girder assemblies have been designed to capture the essential features of reinforced concrete frames responding to earthquake excitation primarily in the plane of the frame. Sizes, materials, and loading rates will be selected to reduce scale effects to a minimum within the limits of the experimental facilities. The experimental variables are (1) Concrete strength, nominally 5,000 and 10, 000 psi; (2) axial unit stress in column, 850 and 1700 psi or one half of "balanced load", and (3) location of yielding, in the column or in the girder. The research is expected to provide: (1) direct conclusions about the effects of the test variables; (2) testing of the currently available hysteresis algorithms using the data from the investigation; (3) development, if necessary, of new hysteresis algorithms to reflect the observed deformations of the column, the girder, and the joint; (4) definition of the domains of confident applicability for the hysteresis algorithms tested or developed; (5) parametric studies of the effects of concrete strength and column yielding on frame response to serve as the base for development of simple design procedures; (6) recommendations of design procedures with defined limits of applicability. ***