深圳北站组合梁抗弯承载力及稳定性分析

组合梁抗弯承载力和稳定性分析对组合梁的结构设计很关键,但组合钢梁上翼缘受混凝土楼板约束,其稳定性分析应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》GB50017—2003采用限制绕弱轴的长细比的方法,未能考虑楼板作用,不适用于组合钢梁稳定性分析。此外,在连续组合梁的负弯矩区,局部稳定性问题也要考虑。结合深圳北站站房楼盖组合梁的工程实例,采用GB50017—2003和欧洲规范EC4,对组合梁抗弯承载力和稳定性进行计算分析,同时,利用通用有限元程序SAP2000对组合钢梁进行弹性屈曲分析,进一步确保了结构的安全。

Bearing Capacity and Stability Analysis for Steel-concrete Composite Beams in Shenzhen North Railroad Station

Analysis of flexural capacity and stability is important in the design of steel-concrete composite beams.Due to the constraint of concrete slab to the beam top flange,the stability of steel-concrete composite beam is different from free steel beams.The method adopted in the Code for design of steel structures GB50017—2003 considers instability by restricting the slenderness ratio about the beam weak axis which takes no consideration for the effect of concrete slab.Therefore,It can not be adopted in the stability analysis of steel-concrete composite beams.In addition,local stability in the negative moment zone should be considered.In the Shenzhen North Railway Station project,GB50017—2003 and Eurocode 4 are adopted to analyze the flexural capacity and stability of steel-concrete composite beams.Apart from that,elastic buckling analysis was performed with finite element program SAP2000 to account for the instability problems mentioned earlier.This analysis ensured the structure security.