墙板与框架梁柱间连接方式对结构抗震性能的影响

Effect of connection modes of wallboard and frame beam-column on structural seismic behavior

墙板与框架梁柱连接方式多种多样,通过对2榀采用不同连接方式的框架-墙板结构缩尺模型进行水平推覆试验,观察其受力变形破坏全过程,研究不同连接方式对结构抗震性能的影响。研究表明,在柱顶水平位移逐渐增大的过程中,两种不同连接方式填充墙的斜撑作用机制均随着墙板的错动、开裂、破坏或平面外偏转而发生变化,相应地,框架梁柱的内力分布发生动态变化,但是两者也呈现出明显的差异。采用图集给出的卡件连接方式时,加载前期墙板与梁柱之间可发生相对位移,该阶段墙板对结构整体刚度贡献相对较小,但L形卡件的设置能够对墙体平面外的位移起到约束作用,直到结构整体失效,墙体始终参与抵抗水平荷载直至出现对角斜拉裂缝;采用企业现行安装工艺进行连接时,拉结钢筋的设置使得轻质墙板与主体框架从受力之始即具有较好的整体性,加载前期对结构的抗侧刚度和抗侧承载力具有较大贡献,但后期因墙板发生平面外偏转而退出工作。

Wallboard and frame beam-column connections are diverse.The pushover test was conducted on 2 pieces of scaling models of frame-wallboard structures with different connection modes to observe the whole process of mechanical deformation and failure,and the effect of different connection modes on seismic performance of structures was studied.The results show that in the process of increasing horizontal displacement at the top of columns,the bracing mechanism of the infilled walls with two different connection modes changes with the dislocation,cracking,failure or out-of-plane deflection of the wallboards.Correspondingly,the internal force distribution of the frame beams and columns changes dynamically,but there are also obvious differences between the two modes.Relative displacement may occur between wallboard and beam-column in the early stage of loading when using the card component connection method given in the code.In this stage,the contribution of wallboard to the overall stiffness of the structure is relatively small,but the setting of L-shaped card component can restrict the out-of-plane displacement of the wall until the whole structure fails,and the wall always participates in resisting horizontal load until diagonal tension cracks appear.When using the current installation technology in enterprises,the setting of tied reinforcing bars makes the light wallboard and the main frame have a better integrity from the beginning of the stress.The pre loading period contributes greatly to the lateral stiffness and the lateral bearing capacity of the structure,but later the wallboard withdraws from work because of the out-of-plane deflection of the wallboard.