竖向非平稳地震下巨型框架有控结构动态特性分析

巨型框架有控结构是近几年人们较为关注的一种新型抗震结构体系.该结构横向跨度很大,且很多约束被解除,在竖向地震力下其巨型梁动态特性亟需研究.文章提出附加柱数量、次结构楼层数量及巨型梁抗弯刚度是影响巨型梁动力响应的重要参数.基于非平稳地震作用情形,分别研究了这些参数对巨型梁动力特性的影响.通过三维曲面图直观地描述了不同时间段上巨型梁动力响应受各参数影响的规律.研究结果表明:附加柱数量存在优化值,当附加柱数量是满布时数量的20%～30%时,巨型梁动力性能最好;巨结构动力响应随次结构楼层数增多而增大;巨型梁刚度也存在优化值,但作者建议该值应结合结构的竖向承载力来考虑选取.

Calculating Dynamic Response of Mega-Beam Subjected to Vertical and Non-Stable Earthquake

Aim. To our knowledge, there is no paper in the open literature dealing with calculating the dynamic response described in the title. Section 1 of the full paper gives the serial-parallel model as shown in Fig. 2. Section 2 points out that the number of additional columns, the number of storeys of sub-structures and the bending rigidity of mega-beam are the three important parameters that have effects on the dynamic response of the mega-beam. Then Section 2 analyzes their effects respectively. Figs. 3(a) and (b) show that when the number of additional columns is 20%～30% of the total number of columns, the vertical dynamic response of the mega-beam is the smallest. Figs. 4(a) and (b) indicate that its vertical dynamic response increases with increasing number of storeys of sub-structures. Figs.5(a) and (b) show that, generally speaking, the increase of the bending rigidity decreases the earthquake resistance of the mega-beam and that, when the rigidity is rather small, it has a short optimal range. The analysis concludes preliminarily that, in designing a mega-beam, an engineer should take into consideration its resistant capacity in the vertical direction.