震损方钢管混凝土柱加固方法对比试验研究

Comparative experimental study on strengthening approach of seismic-damaged CFSST columns

为了研究不同地震损伤程度下方钢管混凝土柱修复加固后的抗震性能,进行了7根柱的模拟地震加载、损伤修复加固和加固后的低周往复荷载破坏试验,研究了外包钢套和碳纤维布两种修复加固方法以及不同地震损伤程度对加固效果的影响。对比了两种方法的加固效果,并分析相应的加固机理。试验结果表明,经过外包钢套合理、可靠的加固柱的承载力和刚度有了显著提高,其抗震性能得到极大的改善;碳纤维布加固对承载力影响不明显,但改善了柱的延性,抗震性能得到了明显提高;在一定损伤程度下,加固柱恢复甚至超过受损前的抗震性能。对于方钢管混凝土柱来说,无论从极限承载力、延性、耗能能力及承载力和刚度退化来看,采用外包钢套、碳纤维布加固均是一种有效的抗震加固方法,就加固效果而言,外包钢套加固效果更优。

In order to study the seismic behaviors of seven repaired CFFST columns,which had different earthquake damage levels. The test included pre-damage loading,rehabilitation of damage and destruction tests under lateral cyclic loading. The reinforcement effects of the methods of enveloped steel and CFRP on different levels of earthquake damage were studied. The reinforcement effects of the two methods were compared,and their reinforcement mechanism is analyzed. The experimental results show that,after reasonable and reliable reinforcement by enveloped steel,the stiffness and ultimate bearing capacity of the columns have significant improvement. The seismic behavior of columns is improved greatly. Influence of CFRP on the ultimate bearing capacity of columns is not obvious,but the ductility and seismic behavior are improved obviously. To a certain extent of damage level,the strengthened columns can reach or even exceed their original performancesbefore earthquake-damage. For CFSST columns,from the aspects of ultimate bearing capacity,ductility,energy dissipation and degradation of strength and stiffness,the methods of enveloped steel and CFRP are effective for seismic strengthening. In terms of reinforcement effect,the method of enveloped steel is better than that of CFRP.