深圳北站组合梁抗弯承载力及稳定性分析

BEARING CAPACITY AND STABILITY ANALYSIS OF STEEL-CONCRETE COMPOSITE BEAMS OF SHENZHEN NORTH RAILWAY STATION

组合梁结构设计中组合梁抗弯承载力和稳定性分析很关键,但由于组合钢梁上翼缘受混凝土楼板约束,其稳定性分析与我国现行规范规定的自由梁弯扭失稳不同,我国钢结构设计规范采用的限制绕弱轴长细比的方法,未能考虑楼板作用,不适用于组合钢梁的稳定性分析。此外,在连续组合梁的负弯矩区,局部稳定问题也要考虑。结合深圳北站站房楼盖组合梁的工程实例,采用我国规范GB 50017-2003《钢结构设计规范》和欧洲规范EC4,对组合梁抗弯承载力和稳定性进行了计算分析,同时,利用通用有限元程序SAP 2000对组合钢梁进行了弹性屈曲分析,进一步确保了结构的安全。所采用的计算分析方法可供同类工程参考。

Analysis of flexural capacity and stability is important to the steel composite beam structural design. Because of the constraint of concrete slab in the top flange beam, the stability of steel-concrete composite beam is deferent from the free steel beam. The method adopted in the Code GB 50017--2003 is to restrict the slenderness ratios of weak axis, no considering of effect of concrete slab. It can not be adopted for the stability analysis of steel-concrete composite beam. In addition, local stability in the negative moment zone should be considered. In the Shenzhen Railway Station project, Code GB 50017--2003 and Eurocode 4 are adopted to analyse the flexural capacity and stability of steel-concrete composite beam, and elastic builcking analysis is also done with finite element program SAP 2000 for furthes ensuring the structure security. The analysis method can be as reference for similar projects.