隔震异形柱框架结构振动台试验研究

Shaking table test of seismic isolated RC frame structure with specially shaped columns

抗震性能的劣势会影响钢筋混凝土异形柱框架结构在工程中的推广和应用,特别是在抗震设防烈度为8度(0.2g)的地区,其高度不超过12 m的规定,严重限制了混凝土异形柱框架在高烈度地区的应用。针对钢筋混凝土异形柱框架结构的抗震性能不足,其应用受限的问题,引入成熟的隔震技术,设计一幢8层(含隔震层)基础隔震钢筋混凝土异形柱框架结构,按1/5的缩尺比例制作试验模型,并进行振动台试验,以研究隔震技术用于钢筋混凝土异形柱框架结构的适应性。通过试验,考察了基础隔震钢筋混凝土异形柱框架结构在各荷载工况下的工作状态和性能。试验结果表明:将隔震技术应用于钢筋混凝土异形柱框架结构,在抗震设防烈度为8度(0.2g)的地区可实现降低一度设防的隔震效果,普通隔震框架结构的设计方法及隔震措施适用于钢筋混凝土异形柱框架结构,采用隔震技术可以扩大钢筋混凝土异形柱框架结构的适用范围。钢筋混凝土异形柱框架结构弹塑性阶段的刚度迅速衰减会对隔震效果产生明显的影响。

The application of RC frame structure with specially shaped columns is impaired by its defect in seismic performance. In particular, requirements on the maximum height of 12 m in seismic fortification intensity 8 （ 0. 2g ） severely limits its application in high intensity zone. Therefore, an up-to-date seismic isolation technique was adopted in this research, to improve the practical application of RC frame structure with specially shaped columns. An eight- storey （including isolation layer） seismic isolated RC frame structure with specially shaped columns was considered. The associated downscale testing model was constructed with a length scale ratio of 1/5 for shaking table test, to study the adaptability of RC frame structure with specially shaped columns combined with seismic isolators. The working status and seismic behavior of base isolated RC frame structure with specially shaped columns under seismic load was investigated. The experimental results show that base isolated RC frame structure with specially shaped columns can be designed with one level lower than the level of earthquake intensity of the fixed basement structures in seismic fortification intensity 8 （ 0. 2g ）. The calculation method and details of seismic design for regular RC frame structure with base isolation can also be used to this special kind of structure. The engineering application of RC frame structure with specially shaped column can be extend by the adopted isolation technology. It has been shown that the isolation effectiveness is significantly affected by the stiffness degradation of RC frame structure with specially shaped columns in elasto-plastic stage.