国产建筑结构用钢板设计指标和可靠度分析

我国现行钢结构设计规范中仅有Q345GJ钢的设计指标。为了补充其他较高强度建筑结构用钢板（主要是Q390GJ钢、Q420GJ钢和Q460GJ钢）的设计指标，对国产建筑结构用钢板的可靠度进行了分析。在对Q390GJ钢、Q420GJ钢和Q460GJ钢的材料性能调研统计的基础上，结合已有的对钢结构几何参数不定性、计算模式不定性的研究，计算得到了建筑结构用钢板抗力不定性的统计参数。利用验算点法，计算得到了建筑结构用钢板在不同荷载组合下的抗力分项系数，并分析了其变化规律。经过比较试算，提出了适用于不同情况下的建筑结构用钢板抗力分项系数和设计强度建议值。最后对上述设计指标进行了可靠度校核。分析结果表明，所提出的建筑结构用钢板设计指标满足GB 50153-2008《工程结构可靠性设计统一标准》的要求，具有一定的可靠性。

Design indexes and reliability analysis of domestic steel plates for building structures

In the current Chinese steel structure design codes, there is only the design value for Q345GJ steel. In order to complete the design values of other grades of steel plates for building structure (hereinafter referred as GJ steel) (mainly Q390GJ, Q420GJ and Q460GJ steels), the reliability of domestic steel plates for building structure was analyzed. Based on the statistical research on the material properties of Q390GJ, Q420GJ and Q460GJ steels and the researches on the uncertainties of geometrical parameters and resistance models of steel structures, the statistical parameters of GJ steel resistance uncertainty were calculated. Utilizing the check-point method, the partial factors for resistance of GJ steel under different load combinations were then obtained. Varying patterns of the partial factors for resistance were also analyzed. After comparisons and trials, this paper has suggested the partial factors for resistance and design values of strength of GJ steel under different circumstances. The reliability of the above design values was calibrated. The result shows that, the design values which are suggested in this paper satisfy the demands in the Unified standard for reliability design of engineering structures (GB 50153—2008) and have sufficient reliability.