配置可更换角钢连接构造的钢框架试验研究

Tests on Moment Resistant Frame Connection with Replaceable Angles

提出了一种适用于抗弯钢框架的可更换组合梁连接构造,钢梁翼缘处由可更换角钢连接,并进行了一系列试验研究。在预期地震作用下,损伤集中于角钢,方便震后更换。同时,考虑到震后建筑功能的快速恢复,使钢梁上方混凝土楼板内发生的裂缝宽度在可接受的微小程度范围内。试验研究分为三个阶段:纯钢梁连接构造的梁柱子结构试验,组合梁连接构造的梁柱子结构试验,以及配置可更换组合梁连接构造的钢框架动力试验。首先简要回顾前两阶段的研究成果,随后报告了第三阶段的研究工作,即配置可更换连接构造的缩尺钢框架的振动台试验。结果表明:形状与尺寸设计中考虑了塑性变形需求与防止净截面断裂破坏风险后,角钢可以有效吸收地震输入的能量,避免其他构件先行损伤;合理设计的连接构造可以避免混凝土严重开裂或者压溃;当主要构件保持弹性或轻微塑性时,快速更换角钢是可行的;更换角钢后,结构的刚度和承载力可以恢复到初始状态。

A concept of moment resistant frame structure with beam-to-column connection by replaceable angles that link the flanges of steel beams has been proposed and experimentally studied.It is expected that structural damage shall be concentrated on the angles during expected earthquakes,and the damaged angles can be easily replaced in the rehabilitation process.Meanwhile,the concrete slab above the steel beam shall develop tolerable cracks only,considering the quick recovery of the building function after an earthquake.Experimental research has been carried out with three phases,including connections of bare steel beam in a sub-structural model,connections of steel-concrete beam in a sub-structural model,and dynamic tests on frame structure model.In this paper,a brief reviewof the results for the first two phases is presented,a report of the third phase study is followed,i.e.,the scaled frame model with the special connection tested on shaking table is reported.The following conclusions can be drawn from the experiment.The angle design about shape and size can guarantee the deformation requirement and avoid the fracture of section,thus the angle can efficiently absorb ground motion energy before the damage of other structural members.Severe cracking or crush of concrete slab can be avoided with properly designed connection details.Quick replacement work is possible when the main structural members keep elastic or experience minor plastic deformation.The structural stiffness and resistance of the repaired frame model may recover to its status as that before damaged.