【摘要】 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。更多还原

【Abstract】 To overcome the existing problems in traditional seismic strengthening methods for RC frame joints,a new method of strengthening RC frame joints with prestressed steel wire ropes was proposed. By reasonably prestressing and anchoring steel wire ropes around column,the shear performance and deformation performance of joints can be improved effectively. Seven joints strengthened with prestressed steel wire rope and two contrastive joints were tested under cyclic loading,and particularly,the influences of strengthening quantity of steel wire ropes,degree of prestressing,setting of the polymer mortar topping and overlapping position of anchorage on the seismic performance of strengthened joints were studied. It is found that the steel wire ropes can improve the shear resistance of joint core area and effectively restraint the development of cracks in joint core area. As a result,the failure mode of specimens was changed from the shear failure of joint core to the flexural failure of beams. After strengthening,the initial stiffness of specimens has no obvious change,while the aseismic performance such as bearing capacity,energy dissipation capacity and ductility can be improved remarkably. During testing,there is no steel wire-rope anchorage failure appearing in the strengthened joints,and the anchorage location has no obvious influence on the bearing capacity,indicating that the anchorage method of steel wire rope is feasible and effective.更多还原