底部加强型钢管混凝土边框带钢筋暗撑组合剪力墙抗震性能试验研究

Experimental study on seismic behavior of bottom enhanced composite shear wall with CFT column frame and concealed reinforcement bracing

为研究底部加强型钢管混凝土边框带钢筋暗撑混凝土组合剪力墙抗震性能及损伤后性能,对普通型和底部加强型试件进行了两阶段低周反复荷载试验,第1阶段试验加载至位移角1/50停止,试件明显屈服损伤,卸载至水平位移恢复初始位置后,进行第2阶段低周反复荷载试验,直至试件严重破坏。分析了各试件的破坏特征、滞回特性、承载力、刚度退化、延性、耗能和应变,给出了承载力简化计算式。研究表明:混凝土墙体未损伤时,底部加强型组合剪力墙较普通型组合剪力墙损伤较轻,承载力提高了8.6%,其他性能接近;混凝土墙体有较大损伤后,底部加强型组合剪力墙剩余承载力高,变形能力大,耗能能力强,抗震性能退化相对较慢,具有较好的抗倒塌能力;给出的承载力计算式可较好的预测其承载力。

In order to study the seismic behavior before and after damage of bottom enhanced composite shear wall with CFT column frame and concealed reinforcement bracing,bottom enhanced and normal shear wall specimens were tested under low cyclic loading. In the first stage test,the specimens were loaded to reach 1 /50 drift ratio and yielding phenomenon was obvious. After the first stage test stopped and the horizontal displacement was unloaded to its initial status. The second stage test was conducted under low cyclic loading until the specimens were seriously damaged.Failure features,hysteretic behavior,bearing capacity,stiffness degradation,ductility,energy dissipation ability and strain were all analyzed. Simplified bearing capacity calculation formulas were presented. Research shows that when the concrete wall suffers no damage,the bottom enhanced composite shear wall gets slighter damage and higher bearing capacity by 8. 6% than normal composite shear wall,but the other behaviors of the two walls are close. After a big part of the concrete wall is damaged,the bottom enhanced composite shear wall has higher residual bearing capacity,larger deformation capacity and stronger energy dissipating capacity than the normal one. Thus, seismic performance degradation speed of the bottom enhanced shear wall is relatively low and the anti-collapse property is good. The presented bearing capacity calculation formula can well estimate the bearing capacity.