主震后损伤的摇摆自复位RC框架剩余抗震能力拟静力试验研究

Study on residual seismic capacity of a damaged self-centering RC frame by quasi-static cyclic loading tests

预应力摇摆自复位RC(reinforced concrete)框架具有优良的抗震性能和震后自复位的能力。然而,对于经历过主震并产生了一定损伤的该类结构,经替换阻尼器等修复手段后结构仍具有的抗震能力水平却未有研究者关注。针对一栋经历过振动台试验并产生了损伤(预制RC梁、柱轻微损伤)的预应力摇摆自复位RC框架模型(1/2缩尺),替换了节点阻尼器,增加了2种新型低损伤填充墙,然后进行了往复加载的拟静力试验,研究了该结构的剩余抗震能力,包括:构件损伤的继续发展、阻尼器的性能、结构变形和自复位能力、低损伤填充墙的表现等,并采用能力谱法对结构的剩余抗震能力给出了评估。研究结果表明,尽管预制梁、柱在主震中产生损伤,但由于预应力筋始终未屈服,更换了节点阻尼器后结构仍具有很好的抗震能力和自复位能力;并且,本文所提出的2种新型填充墙也具有较好的与主体框架协同变形的能力,从而实现了减轻填充墙损伤的设计意图。

Pre-stressed swing self-centering RC(reinforced concrete) frame structure has excellent seismic performance and self-centering ability.However,for this type of structure but damaged during an earthquake,their remain seismic capacity after reparations(such as replacing dampers in the structures) is seldomly concerned.A pre-stressed swing self-centering RC frame(1/2 scale) which was damaged(the RC beams and columns were slightly damaged) during shaking table tests was chosen to investigate its remain seismic capacity by using quasi-static loading tests.Before the quasi-static tests,the structure was repaired first,including replacing the dampers at the nodes and installing two types of novel infilled walls.During the tests,some important performances were investigated,which included the development of the existing damage of the components,the behavior of the dampers,the deformation capacity of the structure,the behavior of the novel low-damage infilled wall.Finally,the remain seismic capacity of the structure was evaluated by using the capacity spectrum method.By the research of this study,it was indicated that although the precast RC beams and columns were damaged during the previous shaking table tests,the repaired structure still possessed great seismic performance and self-centering ability,because the pre-stressed tendons in the structure did not yield.In addition,the two novel infilled walls proposed in this study could deform along with the frame and then achieve the design intention of reducing the damage of the walls.