自复位剪力墙的三水准抗震设防与四水准抗震设防对比研究

基于三水准抗震设防的传统结构虽已逐步控制了建筑倒塌和人员伤亡，但造成的经济损失和社会影响仍然巨大。可恢复功能结构体系震后修复成本较小，能够减少地震造成的经济损失。但三水准抗震设防由于其局限性无法充分体现可恢复功能结构的优越性，因此，前期提出了可恢复功能结构体系的四水准抗震设防目标：小震及中震不坏，大震可更换、可修复，巨震不倒塌。为了比较三水准抗震设防与前期提出的四水准抗震设防在抗震性能、经济性等方面的优劣，以一幢4层自复位剪力墙结构为例，采用基于位移抗震设计方法分别设计了三水准抗震设防大震下与四水准抗震设防巨震下的自复位剪力墙，并进行了低周反复分析与弹塑性时程分析，分析结果表明，四水准抗震设防能够充分发挥可恢复功能结构体系的优越性，且两种抗震设防下，单位长度的自复位剪力墙造价基本相同。

Comparison between three-level and four-level seismic fortifications for self-centering shear walls

Although traditional structures based on three-level seismic fortification objectives can effectively control building collapse and casualties,the economic loss and social impact caused by earthquakes are still huge. Resilient structural system can reduce this kind of economic loss. However,the three-level seismic fortification objective cannot fully reflect the superiority of the resilience structure system due to its limitations. Based on this,four-level seismic fortification objectives were proposed for resilient structural system,i. e. ‘no damage under minor and moderate earthquake,replaceable or repairable under major earthquake,and no collapse under mega earthquake’. In order to compare the advantages and disadvantages of three-level and four-level seismic fortification objectives in terms of seismic performance and cost effectiveness,a four-story self-centering shear wall structure was taken as an example.Displacement-based seismic design method was used to design self-centering shear walls under major earthquake and mega earthquake. Low-cycle analysis and elasto-plastic time-history analysis were performed. The results show that the four-level seismic fortification objective can fully take advantage of the superiority of the resilient structural system and the unit-length cost of the self-centering shear walls is almost the same.