钢骨 钢管高强混凝土长柱承载力可靠度分析

基于《建筑结构可靠度设计统一标准》（GB50068—2001），利用一次二阶矩法（JC法）对钢骨-钢管高强混凝土轴压长柱的极限承载力进行了可靠度分析，研究了可变荷载组合类型、荷载效应比、混凝土强度等级、钢管壁厚、钢骨截面面积、钢材屈服强度及长细比对组合柱承载力可靠指标的影响。分析结果表明，在工程常用长细比范围内，各公式的可靠指标均能满足规范对延性构件可靠度指标的要求；在所研究参数范围内，长柱的可靠度指标随荷载组合和荷载效应比的变化而变化，随混凝土强度等级的提高而增大，随钢管壁厚的增加而有所降低，钢骨截面面积对长柱的可靠指标无明显影响，同时，钢材屈服强度和长细比对各公式可靠指标的影响各不相同。

Reliability Analysis on Ultimate Bearing Capacity of Steel-Reinforced High-Strength Concrete Filled Steel Tubular Slender Columns

The first degree second order moment method (JC method) recommended in Unified Standard for Reliability Design of Building Structures (GB50068--2001) was applied to analyze the reliability of steel reinforced high-strength concrete filled steel tubular slender columns. Several performances were studies,which were the influences of different load combinations, specific values of loads, strength grades of concrete, thickness of steel tube, area of cross-section of structural steel, steel yield strength and slenderness ratio on the reliability of the composite column. It was found that, when the slenderness ratios were within common range, the reliability indexes of the proposed formulae satisfied the demand of GB50068-2001 for plastic material on the whole. And it was concluded that the reliability index varied with the load combination and specific value of loads. The reliability index increased with the increase of concrete strength grade and decreased with the increase of steel tube thickness. Furthermore, steel yield strength and slenderness ratio had different influences on the reliability indexes.