外包钢加固震损钢管混凝土柱的抗震性能试验

Seismic performance of enveloped-steel-strengthened seismic-damaged CFST columns

为了研究外包钢加固震损方钢管混凝土柱的抗震性能,基于现行设计规范,设计并制作了4根方钢管混凝土柱模型,其中,1根为原型对比柱,1根为直接加固柱,2根受到不同程度地震损伤用来模拟中震和大震后采用外包钢加固修复,所有钢管混凝土柱均进行了低周反复荷载试验,以研究外包钢加固震损柱的可行性和有效性,探讨不同地震损伤程度对加固效果的影响。试验结果表明:外包钢合理地加固方钢管混凝土柱后的破坏形态为压弯破坏,满足"强剪弱弯"的抗震设防设计目标;外包钢加固柱的承载力显著提高,延性性能有所增加,抗震性能得到明显改善;在一定损伤程度情况下能加固柱并恢复受损前的抗震性能;从极限承载力、延性系数、能量耗散系数来看,采用外包钢法加固震损柱是一种有效的抗震加固方法。

In order to study the seismic behavior of seismic-damaged concrete-filled square steel tube （ CFSST ） columns strengthened by enveloped steel, based on the current design codes, 4 CFSST column models were designed and manufactured. One column was the original specimen, one column was strengthened by enveloped steel, and the other two columns were pre-damaged to different degrees to simulate moderate and severe earthquakes and strengthened by enveloped steel. The destruction tests on the models under low-cyclic load were carried out. The feasibility and effec-tiveness of seismic-damaged columns strengthened by enveloped steel and the reinforcement effect on different levels of seismic damage were studied. Test results show that the seismic-damaged column strengthened by enveloped steel meets the“strong shear and weak bending” requirements of seismic design, and the failure modes of all columns are compression and bending failure. This reinforce-ment method has a significant effect on increasing the ultimate bearing capacity, ductility and the＆amp;nbsp;seismic behaviors of columns. The study indicated that the rehabilitated columns recover their origi-nal seismic performance before seismic damage under a certain damage level. Based on the test da-ta, namely the ultimate bearing capacity, ductility and the energy consumption coefficient, the strengthening method is an effective method for seismic strengthening.