Experimental tests on full‐scale RC unretrofitted frame and retrofitted with buckling‐restrained braces
Experimental tests on full‐scale RC unretrofitted frame and retrofitted with buckling‐restrained braces
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DOI：
10.1002/eqe.1131
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发表时间：
2012-02
影响因子：
4.5
通讯作者：
L. Di Sarno;G. Manfredi
中科院分区：
文献类型：
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作者：
L. Di Sarno;G. Manfredi
对钢筋混凝土（RC）足尺2层2跨框架建筑进行了实验测试的结果。未加固的框架设计仅用于重力荷载，没有抗震细节;这种框架在本研究中被假定为基准系统。一个类似的钢筋混凝土框架进行了加固屈曲约束支撑（BRB）。使用位移控制的静力和循环侧向荷载对两种原型的地震结构性能进行了实验研究。模态响应特性的原型也确定之前和之后的结构损伤的发生。动态响应分析的结果被用来评估现有的设计规则的弹性和非弹性振动周期的估计。同样，将等效阻尼值与规范基础关系进行比较。结果发现，现有的公式需要进行重大修订时，他们被用来预测结构响应的钢筋混凝土框架建筑。采用防屈曲支撑作为支撑体系时，结构的等效阻尼比可提高50%以上。对于加固后的框架，超强Ω和延性μ分别为1.6和4.1;估计的R‐系数为6.5。防屈曲支撑是提高现有钢筋混凝土框架结构抗侧移刚度、抗侧移强度和耗能能力的有效手段。基础系统和现有上盖构件一般不会承受过大应力，因为施加于它们的地震需求可由防冲支板的轴向刚度和屈服力控制。版权所有© 2011约翰威利父子有限公司.
The results of experimental tests carried out on reinforced concrete (RC) full‐scale 2‐storey 2‐bays framed buildings are presented. The unretrofitted frame was designed for gravity loads only and without seismic details; such frame was assumed as a benchmark system in this study. A similar RC frame was retrofitted with buckling‐restrained braces (BRBs). The earthquake structural performance of both prototypes was investigated experimentally using displacement‐controlled pushover static and cyclic lateral loads. Modal response properties of the prototypes were also determined before and after the occurrence of structural damage. The results of the dynamic response analyses were utilized to assess the existing design rules for the estimation of the elastic and inelastic period of vibrations. Similarly, the values of equivalent damping were compared with code‐base relationships. It was found that the existing formulations need major revisions when they are used to predict the structural response of as‐built RC framed buildings. The equivalent damping ratio ξeq was augmented by more than 50% when the BRBs was employed as bracing system. For the retrofitted frame, the overstrength Ω and the ductility µ are 1.6 and 4.1, respectively; the estimated R‐factor is 6.5. The use of BRBs is thus a viable means to enhance efficiently the lateral stiffness and strength, the energy absorption and dissipation capacity of the existing RC substandard frame buildings. The foundation systems and the existing members of the superstructure are generally not overstressed as the seismic demand imposed on them can be controlled by the axial stiffness and the yielding force of the BRBs. Copyright © 2011 John Wiley & Sons, Ltd.