大跨度固接钢-混凝土组合楼盖关键技术分析

Key techniques of large-span steel-concrete composite floor structures with fixed beam-column connections

固接钢-混凝土组合楼盖相比于传统混凝土楼盖、纯钢结构楼盖及铰接组合楼盖具有跨度大、结构高度小、用钢量少、受力性能好、整体性强等优势。目前,限制大跨度固接组合楼盖推广应用的主要问题是缺乏完善的实用分析计算与设计方法。以某高层建筑综合体底层大跨度结构为实际工程背景,基于内力计算、组合梁截面设计、舒适度验算以及节点设计等方面,研究大跨度固接组合楼盖的实用分析计算与设计方法。研究结果表明:大跨度固接组合楼盖的舒适度验算应采用基于动力响应法的评价标准,主梁梁端的负弯矩区截面的长度约为0.2倍梁长;考虑地震作用组合工况,对主梁负弯矩设计值影响不显著,大跨度固接主梁的内力计算在设计时可以仅考虑竖向静载工况作用。

The steel-concrete composite floor structure system with fixed beam-column connections has the advantages of larger-span, smaller structural height, less steel tonnage, better mechanical performance and stability when compared with the classic reinforced concrete floor structure,steel floor structure and composite floor structure with hinged beam-column connections. But the composite floor structure system with fixed beam-column connections has not been widely used. One of the main causes to this phenomenon is the lack of complete and reliable analysis and design methods for this structural system. Aiming at this problem,the present study discussed the method of calculating internal forces,designing sections of the fixed primary beam,evaluating the vibration behavior and designing the fixed beam-column connections on the basis of a real engineering case. It is concluded that the evaluation of the vibration behavior of large-span steel-concrete composite floor structure system with fixed beam-column connections should use the dynamic response-based method. It is also suggested that the length of the part using the hogging moment section at the ends of the primary beam can be determined as 0. 2l( l is the length of the beam). In addition,the internal forces of the large-span fixed primary beams can be approximately calculated by considering the vertical static load effect without the influence of the lateral load effect such as the earthquake effect.