中低剪压比框架节点抗震机理的试验研究  

Experimental Study on Shock-resistant Mechanism of Frame Joints with Low to Moderate Shear-Compression Ratio

作　　者：傅剑平[1] 陈小英[1] 陈滔[1] 白绍良[1] 

机构地区：[1]重庆大学土木工程学院,重庆400045

出　　处：《重庆建筑大学学报》2005年第1期41-47,共7页Journal of Chongqing Jianzhu University

基　　金：国家自然科学基金资助项目(59878056)

摘　　要：为了识别节点核心区的传力机理,特别是其中水平箍筋的作用和轴压比的影响,作者所在的研究集体自20世纪90年代后期以来完成了钢筋混凝土平面框架中间层中间节点的抗震性能系列试验。现首次陆续公开发表此项研究成果。介绍了6个接近足尺的中到低剪压比(Vj/fcbjhj≤0.20)试件的试验结果。其中主要的新结论是:(1)核心区水平箍筋除去平行受力方向箍筋参与形成抗剪桁架机构外,所有箍肢还随组合体位移延性增大对核心区斜压混凝土发挥越来越大的约束作用,对核心区斜压型剪切破坏起重要控制作用;(2)在剪压比未超过0.17的节点中,轴压比的增大能扼制核心区交叉斜裂缝的发育,减缓梁筋贯穿段的粘结滑动和屈服渗透,提高节点发生剪切破坏时组合体的位移延性;但剪压比大于0.17后,除减小粘结滑移外,其余有利作用基本消失,但尚无不利作用;(3)节点的剪切变形在组合体总变形中占有大小不等的份额,不容忽视。首次给出了合理的节点抗震性能评价准则及方法。In this paper, the test results of 6 nearly full-scale specimens from the series of seismic behavior test on the interior joints with low to moderate shear-compression ratio (Vj/fcbjhj [less-than or equal to] 0.20) in reinforced concrete plane frame are introduced. The primary new conclusions from them are: 1. For the level stirrups in the core area, except for those, parallel to the direction of the force and functioning in forming the anti-shear truss mechanism, all stirrup legs develop stronger confinement to the diagonal compressive concrete and determine the diagonal compression shear failure in the core area; 2. In the joints with shear-compression ratio below 0.17, the increase of axial load ratio can restrain the development of the cross-inclined cracks in the core area, decelerate the bond slip and yield penetration of the beam bars through the joints and enhance the displacement ductility of the combination, when the joints fail. In those joints with shear compression ratio above 0.17, the increase of axial load ratio cannot give advantages stated above, but without unfavorable result; 3. The shear deformation of the joints accounts for various shares in the total deformation of the combination and cannot be neglected. In this paper, the rational rules and methods for evaluating the seismic behavior for joints are firstly proposed.

关 键 词：钢筋混凝土 框架 抗震设计 梁柱节点 

分 类 号：TU352.11[建筑科学—结构工程]