钢桥塔截面设计研究

ANALYSIS ON THE SECTION DESIGN OF STEEL BRIDGE TOWER

基于实际工程对4种钢桥塔备选截面进行数值模拟和相关规范建议值计算,得到极限承载力、失稳模态、变形及应力规律,通过对比发现组合式截面钢桥塔较其他3种截面更适合该桥。组合式截面钢桥塔极限承载力较大,极限状态下压应力分布更加合理。计算结果表明:考虑结构初始缺陷及材料、几何双重非线性第二类稳定计算所得的承载力与相关规范建议承载力吻合较好,与美国规范建议值相差在12%以内。在钢桥塔的选型中,组合式钢桥塔是一种较为有竞争力的方案。

According to the engineering practice, a numerical simulation and specification recommended value calculation on the four steel bridge tower sections were carried out. The ultimate bearing capacity,load bucking mode,deformation and strain rules were obtained. Compared with the other three steel bridge tower sections the combined section is more suitable for this bridge. The ultimate bearing capacity of the steel bridge tower with combined section was larger and the compressive stress distribution under ultimate state was more uniform. The results showed that the ultimate bearing capacity considering material nonlinearities and geometric nonlinearities,as well as the structural initial imperfection was close to the specification recommended value. The ultimate bearing capacity and American Specification recommended value only had 12% deviation. The combined steel bridge tower is a kind of competitive plan.