重型钢结构厂房屋盖系统方案比较

Comparison of Roof Systems for a Heavy Industrial Steel Building

针对某吊车吨位达到650t的重型钢结构厂房,比较了桁架屋盖体系和楔形梁屋盖两种方案的结构自振周期、屋盖用钢量、主结构变形、主要构件应力比、屋盖刚度对实腹式上柱受力的影响,以及按照平面框架分析和空间分析两种情况下结构变形。比较和分析结果表明,采用楔形梁方案能满足结构整体受力性能的要求,没有增加屋盖的用钢量,且变形满足现行规范要求。屋盖刚度、变阶柱刚度比值对上柱受力影响较大。对空间分析中振型阶数的选取进行了探讨,结果表明,进行空间分析时,振型阶数的选取对结构反应影响较大。

Heavy industrial steel buildings are mainly constructed with trussed or grid roof system instead of tapered beam roof system, which has never been adopted in such constructions in China. Detailed comparison is done concerning the natural vibration period, steel consumptions, deformation, stress ratios and influence of the roof stiffness to the top columns of the above roof systems. For a heavy industrial building with cranes of tonnage up to 650t, the results show that the tapered beam roof system satisfies the code requirements. Moreover, selection of nominal modes of the building for seismic spectrum analysis is discussed. The results indicate that the local modes have a great effect on the structure responses. The number of the modes should be enough to consider the influence of the local modes in spatial analysis.