大跨度钢屋盖结构整体提升施工过程力学模拟分析

Simulation analysis on integral lifting of large-span steel roof structures during construction process

西安东航维修基地新机库钢屋盖采用正交斜放焊接球空间网架体系。对该钢屋盖结构的同步提升过程进行施工力学模拟。通过不同步提升分析,提出了"单、隔点组合不同步分析法",并给出减轻提升不同步性的措施。研究表明:提升过程中将稳定计算中强度设计值乘以折减系数0.95是合理的;结构在同步提升状态下受力和变形均满足规范要求,整个提升过程安全可靠;某个提升点施加位移差只会影响该点附近构件的内力,并对相邻较短构件和较近间距的相邻提升点提升力产生较大影响;对相邻提升点同时施加位移差的情况不需要单独考虑,但隔点同时施加位移差的情况不能忽略;"单、隔点组合不同步分析法"包络了所有不同步提升中的不利情况,计算过程简便,可以在大跨度钢屋盖结构的提升不同步性计算中广泛应用;结构在脱离支撑时先提升提升力较小的吊点,在就位时先落提升力较大的吊点,可以减轻提升不同步性。

The steel roof of hangar for the China Eastern Airline adopted the orthogonal diagonal welded spherical grid structure. The synchronous integral lifting of the steel roof of hangar for the China Eastern Airline was analyzed. The paper considers displacement difference of the lifting points to analyze the lifting process and the asynchronous method of single and interlaced points was introduced. The analytical results show that it is reasonable to multiply design value of strength by reduction factor 0.95 and the structure in synchronous lifting process is security. The changes of displacement difference of some lifting points have great influence on internal force of the neighboring members and lifting points. The displacement difference of interlaced lifting points can not be neglected, compared with the displacement difference of neighboring lifting points. It is feasible to apply the asynchronous method of single and interlaced points to analyze the asynchronous lifting process of large-span steel roof structures. The paper also gives some methods to reduce displacement difference of the lifting points ： lift lifting points of smaller force and lifting points of larger forces have its place first.