密肋槽钢修复薄钢板剪力墙抗震性能研究

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

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。

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 stepⅠ,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 stageⅡ,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.