钢管混凝土组合长柱低周往复抗震性能试验

Experimental study on seismic performance of concrete filled steel tube composite long columns under low-reversed cyclic loading

为了研究钢管混凝土组合长柱的抗震性能,设计并制作了两个组合长柱试件,一个为空钢管组合柱,另一个在中柱灌有混凝土,对其进行低周反复荷载试验,试验过程中测取了试件的反力、水平位移、内力变化过程并观察试件受力的全过程与破坏形态,分析了试件的滞回曲线、骨架曲线、位移延性、刚度退化与耗能能力等。试验结果表明:两个试件的最终破坏均出现在上部单柱,主要表现为钢材的局部屈曲;试件的滞回曲线饱满,随着水平位移的增加,滞回曲线端部出现比较小的紧缩;灌混凝土组合柱的耗能能力高于空钢管组合柱,灌混凝土组合柱的位移延性系数大于3.0,试件破坏时,等效粘滞阻尼系数大于0.2。基于试验结果,对组合柱"中震可修"性能进行了讨论与分析。

In order to study the seismic performance of concrete filled steel tube composite long columns, two com- posite long columns with and without concrete in the middle column were designed and tested under low-reversed cyclic loading. The specimen＇s reaction force, horizontal displacement, internal force were carefully recorded dur- ing the experiment. The entire loading process eton curve, displacement ductility, stiffness d and failure mode were carefully observed, the hysteretic curve, skel- egradation and dissipation capacity were analyzed. The test results showed that： the ultimate failure of the composite columns under low-reversed cyclic loading was controlled by the upper single column, and the failure mode were the local buckling of the steel. The hysteresis curve of the speci- mens were plump and had a small constriction in the end with the increase of horizontal displacement. The dissipa- tion capacity of the specimen with concrete in the middle column was better, and the displacement ductility of the specimen with concrete in the middle column was more than 3.0, and it＇s equivalent viscous damping coefficients at failure point was more than 0.2. Based on the test results, the repairable under moderate level of earthquake of the specimens were discussed and analyzed.