多层强边柱冷成型钢结构体系抗震性能分析

Seismic analysis on mid-rise cold-formed steel structure with reinforced end studs

多层强边柱冷成型钢结构能够促进低层冷成型钢结构向多层住宅结构体系的发展.为了分析多层强边柱冷成型钢住宅结构体系在地震作用下的动力特性,本文提出了该类结构的主要抗侧构件强边柱冷成型钢组合墙体可以考虑节点实际连接性能的简化计算模型,进而得到整体结构抗震计算模型;根据作者前期开展的墙体抗剪试验结果并结合国外规范,提出此类结构在地震作用下的侧向变形验算指标;对整体结构进行抗震性能研究.结果表明:考虑节点连接的等代拉压杆模型能够准确预测此类结构的实际受力特性;将1/300和1/75分别作为此类结构在多遇和罕遇地震作用下的层间位移角限值是安全可靠的;在9度罕遇地震作用下,此类结构不会发生倒塌破坏;进行此类结构设计时,不宜采用两个方向刚度差异过大的抗剪墙体组合,同时应重点加强结构沿墙体开洞率较大方向的墙体抗剪强度;在特别高烈度地区进行此类结构设计时,应兼顾墙体抗剪强度和墙体边柱的竖向承载能力,避免结构因墙体边柱的压屈破坏而导致整体结构失效.

Mid-rise cold-formed steel （ CFS） structure with reinforced end studs can promote the development of mid-rise CFS residential buildings from low-rise ones. To analyze the dynamic characteristics of mid-rise CFS residential structures with reinforced end studs under earthquakes, a simplified calculation model of CFS shear wall with reinforced end studs, which is the main lateral load-bearing structural component of the structure, was proposed. The proposed model could consider the real behavior of beam-column joint, and then the seismic calculation model of the whole structure was further obtained. Lateral design objectives for the structure under earthquake were proposed according to abroad specification and previous shear wall test results that performed by authors, and seismic analysis on a mid-rise CFS structure with reinforced end studs was carried out. The results show that equivalent-bracing model considering the mechanical behavior of beam-column joint can precisely predict the seismic performance of the structure. It is safe and reliable that 1/300 and 1/75 being taken as the elastic and inelastic storey drift limits of the structure under frequent and severe earthquake, respectively. Mid-rise CFS structure with reinforced end studs will not collapse under severe earthquake with a degree of 9. It is not suitable to adopt shear wall combination with large difference in stiffness between two directions, and the shear strength of the walls along the direction with larger opening rate should be strengthened emphatically. In areas of particularly high seismicity, both shear strength of the wall and vertical bearing capacity of end studs should be taken into account to avoid overall failure, which is caused by end studs＇ buckling.