摘要
对钢筋混凝土框架顶层L形边节点及T形中节点的抗震性能进行了试验研究。根据节点裂缝特征、荷载-变形滞回曲线、梁柱纵筋应变曲线及节点核心区周围诸力分布特点等试验结果,分析了节点的各种破坏模式及不同破坏模式对节点强度的影响。比较了中日两国规范节点强度设计值与试验结果的吻合性。结果表明:在满足节点内构件纵筋锚固充分的前提下,L形节点在梁柱相对关闭方向的传力机构为扇形斜压杆机构,难以被"剪压"坏,节点抗剪强度在混凝土圆柱体抗压强度的0.2倍以上;张开方向的节点强度由受弯传力机构决定,节点强度为关闭方向的0.7倍左右。T形节点的抗剪强度在混凝土圆柱体抗压强度的0.2倍左右,梁筋在节点内粘结性能的显著衰减使节点强度低于├形中间层边节点。
The experimental study on seismic performance of reinforced concrete L-shaped and T-shaped joints on frame top story was carried out. Various failure modes of joints and the influence of different failure modes on joint strength were analyzed based on the test results such as crack patterns of joints, load-displacement hysteresis loops, strain curves of beam bars and column bars. Anastomosis of test results and design values calculated by China code and Japan code on joint strength was compared. The results showed that when having enough anchorage of structure component bars passing through joints, force resisting mechanism of L- shaped joint subject to loading in closing direction is sector and hard to fail in due to shear compression, the joint shear strength is larger than 0.2 times of concrete cylinder compressive strength, and the joint strength in opening direction is governed by moment resisting mechanism, the joint strength is 0.7 times of that in closing direction. The shear strength of T-shaped interior joint is about 0.2 times of concrete cylinder compressive strength, and the joint strength is smaller than that of ⊥→-shaped exterior joints due to the significant bond deterioration of beam bars passing through joints.
出处
《建筑结构》
CSCD
北大核心
2009年第9期43-48,共6页
Building Structure
关键词
框架顶层节点
破坏形式
抗剪强度
抗弯强度
粘结衰减
joints on frame top story
failure modes
shear strength
bending strength
bond deterioration
