装配式冷弯薄壁型钢-泡沫混凝土组合墙体抗震性能试验研究

Experimental study on seismic behavior of prefabricated cold-formed thin-walled steel-foam concrete composite walls

为推动冷弯薄壁型钢房屋结构体系的发展,提高其装配化率,提出3种干法装配形式,用于翼缘和腹板墙肢的连接。对3个不同装配形式的冷弯薄壁型钢-泡沫混凝土组合墙体和1个现浇墙体进行拟静力加载试验,分析各墙体的破坏模式、承载力、抗侧刚度、耗能及延性等指标,研究3种干法连接的可靠性及不同装配形式下墙体抗震性能的差异。结果表明:墙体的破坏主要集中在腹板墙肢,立柱之间的墙面板及内部填充的泡沫混凝土出现交叉斜向裂缝,水平横撑发生局部屈曲,翼缘墙肢在底部出现几道水平和竖向裂缝;设计的3种干法连接安全可靠,构件均先于连接处发生破坏;与现浇墙体相比,装配墙体的承载能力和初始刚度有所降低,但变形及耗能能力较强;与腹板拼接墙体相比,对拉连接墙体的峰值荷载、初始刚度和总耗能分别提高了36.5%、15.0%和12.5%,L件连接墙体的峰值荷载和总耗能分别提高了22.8%和54.5%,初始刚度降低了21.5%;综合考虑3种装配形式墙体的抗震性能、运输条件及施工难易程度等因素,优选L件连接的装配形式用于工程实际。基于叠加原理,推导了装配式组合墙体的抗侧刚度,并验证了计算方法的正确性。

In order to promote the development of cold-formed thin-walled steel building structure system and improve its assembly ratio,three dry assembly forms of connection between the flanges and webs of the walls were proposed.To study the seismic behavior of the composite walls,three different prefabricated cold-formed thin-walled steel-foam concrete composite wall specimens and one cast-in-place wall specimen were tested under low-cycle reciprocating load.The failure mode,bearing capacity,lateral stiffness,energy dissipation and ductility of specimens were analyzed.The reliability of the three types of dry connection and the differences in seismic performance of the walls with different assembly forms were studied.The results show that the failure of the wall is mainly concentrated in the web pier,the wall panels between the columns and the foam concrete filled inside appear crossed oblique cracks,the horizontal braces are subjected to local buckling,and only a few horizontal and vertical cracks appear at the bottom of the flanges of the wall pier.The three dry connections are safe and reliable,and the components fail before the joint.Compared with the cast-in-place counterpart,the bearing capacity and initial stiffness of the assembly specimens are lower,but the deformation and energy dissipation capabilities are higher.Compared with the web spliced wall,the peak load,initial stiffness and total energy dissipation of the tensile connection wall are increased by 36.5%,15.0%and 12.5%,respectively,and the peak load and total energy dissipation of the L-joint wall are increased by 22.8%and 54.5%,respectively,the initial stiffness is reduced by 21.5%.Considering the seismic performance,transportation condition and construction difficulty of the three assembly forms comprehensively,the assembly form of L-shaped connector is preferred for engineering practice.Based on the principle of superposition,the lateral stiffness of the prefabricated composite wall was deduced,and the accuracy of the calculation method was verified.