防屈曲支撑加固既有混凝土框架结构拟动力试验研究

PSEUDO-DYNAMIC TEST OF EXISTING RC FRAME STRUCTURE RETROFITTED WITH BUCKLING-RESTRAINED BRACES

参照建于20世纪70年代末的具有代表性的八层混凝土框架结构,按照1∶2.5的比例进行缩尺,制作了一个两榀两层三跨的混凝土框架子结构模型。采用外贴防屈曲支撑混凝土框架的方式分别加固子结构模型每榀的中间跨,两榀框架的加固方式分别为植筋加固和抗剪键加固。对加固后的模型进行拟动力试验。试验结果表明,罕遇地震下结构的变形能够满足规范的要求,且依然具有变形的潜力;两种加固方法均安全可靠;防屈曲支撑加固后混凝土框架结构的抗震性能明显提高,防屈曲支撑耗散掉了大部分的地震能;与普通混凝土框架结构的滞回曲线相比,本结构具有更好的变形以及耗能能力。

A two-storey RC-frame-structure model was made as a substructure of an existing eight-storey RC building built in late 1970s with a scale of 1 ： 2.5. It was retrofitted with two buckling-restrained-braces frames by means of embedded bars and shear connectors respectively on the middle span of the three-span RC model structure on both sides. Pseudo-dynamic test had been carried out on the model frame substructure. The test results showed that the connecting methods of buckling-restrained braced frame performed excellent together with the existing frame structure under cyclic loading, and buckling-restrained braces increased the seismic performance of model structure, seismic energy to the structures during earthquake was mainly absorbed by buckling-restrained braces, leading to less damage on structure elements.