论文部分内容阅读
针对目前RC框架节点抗震加固方法存在的问题,提出一种新型预应力钢丝绳加固RC框架节点加固技术。为验证该节点加固技术的有效性,开展7个加固试件及2个对比试件在水平低周往复荷载作用下的抗震性能试验。重点研究钢丝绳加固量、预应力度、聚合物砂浆面层设置和搭接锚固位置等对加固节点抗震性能的影响,对各试件的破坏形态、滞回特性和变形特征等抗震性能指标进行分析。试验结果表明:预应力钢丝绳能有效抑制节点核心区裂缝的开展,提高节点核心区抗剪承载能力,实现破坏位置转移和破坏形态改变,加固试件的破坏形态由对比试件的节点剪切破坏转变为梁端弯曲破坏。加固后试件的初始刚度无明显变化,试件承载能力、耗能能力和延性等抗震性能指标均明显提高。试验过程中所有加固试件钢丝绳均未出现锚固失效,锚固位置对承载力无明显影响,表明该锚固方式是可行有效的。研究成果可为大量既有RC框架节点的抗震加固提供技术支持。
Aiming at the existing problems of seismic strengthening method for RC frame joints, a new type of RC frame reinforcement technology with prestressed steel wire rope is proposed. In order to verify the effectiveness of this node reinforcement technology, the seismic performance tests of seven reinforced specimens and two comparative specimens under horizontal low cycle reciprocating loads were carried out. The research focuses on the influence of the amount of steel wire rope reinforcement, prestressing force, setting of polymer mortar surface and lap anchorage on the seismic performance of reinforced joints. The seismic performance indexes such as failure morphology, hysteresis and deformation characteristics are analyzed. . The experimental results show that the prestressed wire rope can effectively suppress the crack initiation in the core zone, improve the shear bearing capacity in the core area of the node, and achieve the transfer of the damage location and the failure of the damaged form. The failure morphology of the strengthened specimen is controlled by the shear failure of the node Bending into bending damage. After the reinforcement, the initial stiffness of the specimen has no obvious change, and the bearing capacity, energy dissipation capacity and ductility and other seismic performance indexes of the specimens are obviously improved. During the test, no anchoring failure occurred on all the reinforcing steel wire ropes, and the anchor position had no significant effect on the bearing capacity, indicating that the anchoring method is feasible and effective. The research results can provide technical support for the seismic strengthening of a large number of existing RC frame joints.