现代高层建筑向多功能、综合用途发展。在同一竖直线上,顶部楼层布置住宅、旅馆;中部楼层作为办公用房;下部楼层作商店、餐馆、文化娱乐设施。不同用途的楼层,需要不同大小的开间,需要不同的结构布置形式。在建筑功能上,上部需要小开间的轴线布置,需要较多的墙体,以满足旅馆和住宅的要求;中部办公用房则需要小和中等大小的室内开间,可以在柱网中布置一定数量的墙体,下部则希望有尽可能大的自由活动空间,柱网要大,墙体要尽量少。为了满足建筑功能的要求,在进行结构设计时就必须设置转换层。钢管混凝土桁架式转换层是在钢筋混凝土桁架式转换层的基础上演变而来的一种新型的转换层结构体系,但钢管混凝土桁架式转换层在以前的工程实例中尚未得到运用,主要原因是因为缺乏这类转换层的理论及实验研究 Modern high-rise buildings develop into multi-purpose and comprehensive uses. On the same vertical line, houses and hotels are arranged on the top floor; the middle floor serves as office space; and the lower floors serve as shops, restaurants, and cultural and recreational facilities. Floors for different purposes require different size bays and require different layouts. In the function of the building, the upper part needs the layout of the axis of the small bay, which requires more walls to meet the requirements of the hotel and residence; the central office building needs the small and medium-sized indoor bay, which can be arranged in the column net. The lower part of the wall is expected to have as much freedom of movement as possible. The pillar net should be large and the wall should be as small as possible. In order to meet the requirements of architectural functions, a conversion layer must be provided when the structural design is performed. The concrete-filled steel tubular truss conversion layer is a new type of conversion layer system based on the reinforced concrete truss conversion layer, but the concrete-filled steel tubular truss conversion layer has not been used in previous engineering examples. The main reason is that Because of the lack of theoretical and experimental research on this type of conversion layer