目前,在我国火电厂厂房的设计和施工中,常遇到如图1所示的多层钢筋混凝土框架,其预制吊装分段位置如图中横短线所示,因此,它们在分段吊装时吊件实为门形.这种框架横梁断面往往小于柱断面,且两柱断面不等,即这种门形架为非对称结构.在这种情况下起吊时,因起吊吊点受力不均,两柱不能始终保持平行,极易使横梁受扭.而这类框架横梁在设计时一般不考虑其抗扭能力,因而往往造成横梁裂缝甚至完全断裂,成为厂房吊装中的突出问题. At present, in the design and construction of thermal power plant buildings in China, a multi-layer reinforced concrete frame is often encountered as shown in Fig. 1. Its prefabricated hoisting and disassembling positions are shown in the horizontal and vertical lines in the figure. Therefore, when they are being hoisted in sections, The hangers are actually door-shaped. This frame cross-section is often smaller than the cross-section of the column, and the cross section of the two columns is not equal, that is, this kind of gantry is asymmetric structure. In this case, when lifting, the lifting point is not subjected to force. In fact, the two columns cannot always be kept parallel, and it is easy to make the beams torsion. Such frame beams are generally not considered in their ability to resist torsion when they are designed, and thus often cause cracks or even complete fracture of the beams, which becomes a prominent problem in the lifting of the plant.