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

9320150本项目将调查两个参数对框架反应的影响：(A)高强混凝土和(B)柱屈服。缺乏物理数据来支持目前关于高强混凝土和柱子屈服影响的现有假设。虽然这两个参数属于不同的类别(一个是材料属性，另一个是设计方案)，但由于缺乏对这两种情况的一般理论理解，导致在钢筋混凝土建筑抗震设计中限制选择的效果相同。设计了10个钢筋混凝土柱-梁组合试件，以反映钢筋混凝土框架在地震激励下的基本特征，主要是在框架平面内。将选择尺寸、材料和装载率，以在实验设备的限制范围内将规模效应降低到最低限度。试验变量是(1)混凝土强度，名义上为5000和10000磅/平方英寸；(2)柱中的轴向单位应力，850磅/平方英寸和1700磅/平方英寸，或“平衡荷载”的一半；(3)屈服位置，在柱中或在梁中。这项研究有望提供：(1)测试变量影响的直接结论；(2)使用调查数据测试当前可用的滞回算法；(3)如有必要，开发新的滞回算法，以反映柱、梁和节点的观测变形；(4)定义测试或开发的滞回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研究，作为开发简单设计程序的基础；(6)建议具有明确适用范围的设计程序。***

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. ***