密肋槽钢修复薄钢板剪力墙抗震性能研究

薄钢板剪力墙的屈曲荷载低,在地震作用下会产生较大残余变形,影响二次抗震性能。为此提出锚固密肋槽钢的方法修复震后损伤钢板剪力墙,根据附加肋板的受力模型,推导了修复内嵌钢板所需肋条间距限值公式。为研究该公式的合理性及修复后结构的抗震性能,对一榀单跨双层薄钢板剪力墙施加了两阶段低周往复荷载,即第Ⅰ阶段加载至1/130位移角,以达到在该加载步模拟地震损伤的目的,之后安装密肋槽钢修复内嵌钢板;第Ⅱ阶段将修复加固后结构加载至破坏,研究其抗震性能变化。结果表明:加劲肋具有足够刚度,可以有效抑制内嵌钢板残余变形;修复后结构破坏模式合理,滞回曲线饱满,附加肋板可以有效提高其耗能能力;结构刚度及延性较高,刚度相较原结构提升14%,位移延性系数达到3. 12,具有良好的变形能力。

Seismic behavior of thin steel plate shear wall repaired by multi-ribbed channel grid

The buckling strength of thin steel plate shear wall is low. Therefore, earthquakes will produce residual deformation to the embedded steel plate, which affects the post-earthquake performance of the structure. The method of anchoring multi ribbed channel grid to repair the damaged steel plate shear wall was proposed. The size limit of the multi-ribbed grid was derived according to the stress model of the additional ribs. To identify the rationality of the proposed approach and to study the performance of the repaired structure, a single span, two-story experimental specimen was tested under low cycle reversed loading by two steps. In step Ⅰ, the specimen was first loaded to the maximum inter story displacement angle of 1/130 to simulate earthquake damage. Then the specimen was repaired. In stage Ⅱ, the repaired structure was loaded to damage. The test result shows that the multi-ribbed grid is rigid enough to suppress the residual deformation of the embedded steel plate. The repaired structure has a reasonable failure mode. The hysteresis loop is plump, and the additional ribs effectively increase its energy dissipation. The stiffness and ductility of the structure are satisfactory. The stiffness of the repaired structure is 14% higher than that of the original one. The ductility coefficient reaches 3.12, which means the structure has a good deformation capability.