自复位剪力墙结构四水准抗震设防下基于位移抗震设计方法

Displacement-based seismic design of self-centering shear walls under four-level seismic fortifications

与传统剪力墙结构体系相比,自复位剪力墙结构体系在地震作用下,会将材料非线性问题转为体系非线性问题,具有整体变形能力强、残余位移小的特点,因此,亟需针对自复位剪力墙结构,提出具有更高抗震设防要求的抗震设防目标以及相应的设计方法。基于GB 50011—2010《建筑抗震设计规范》中"小震不坏、中震可修、大震不倒"的三水准抗震设防目标,与2015年颁布的第五代《中国地震动参数区划图》相适应,提出了可恢复功能结构体系"小震及中震不坏,大震可更换、可修复,巨震不倒塌"抗震设防四水准目标。采用了基于位移的抗震设计方法进行自复位剪力墙结构设计。以一幢自复位剪力墙结构为例,给出四水准抗震设防目标下的基于位移设计方法算例,并对其进行弹塑性时程分析,验证了所提出的四水准抗震设防目标下基于位移抗震设计方法的有效性,该方法也适用于其他可恢复功能结构体系设计。

Compared with traditional shear wall structures, self-centering shear wall structures transfer material nonlinearity into geometrical nonlinearity under seismic input,so they are capable of undergoing large global deformability and small residual drift.Therefore, seismic design with higher seismic fortification objectives and the corresponding seismic design method are needed for self-centering shear wall structures. In corresponding with the three-level seismic fortification objectives in Chinese seismic code "no damage under minor earthquake, repairable under moderate earthquake, and no collapse under major earthquake", a four-level seismic fortification objective was proposed as "no damage under minor and moderate earthquake, replaceable or repairable under major earthquake, and no collapse under mega earthquake" based on the seismic ground motion parameter zonation map of China. Since self-centering shear wall structures had large deformation demand, the displacement-based seismic design was applied for this kind of structures. A design example of self-centering shear wall structures was presented. Elasto-plastic time history analyses were executed, and the results validated the seismic design method. The proposed displacement-based seismic design considering four-level seismic fortifications can also be applied to other resilient structures.