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为了探讨大尺寸钢管混凝土柱的初始偏心和开洞插管初始缺陷对其承载力的影响规律,以某钢管混凝土拱桥主拱肋Φ1 200×24 mm钢管为原型,采用1∶2.4,1∶4.8两种几何比例尺分别制作了长径比为3∶1的钢管混凝土柱试件,进行了轴压和偏压试验,并将承载力试验结果与中国现行相关规范的承载力计算结果进行了对比。结果表明:钢管混凝土柱的承载力试验值均大于规范计算值,大尺寸试件和小尺寸试件轴压承载力与规范的比值相差不大,但是大尺寸试件的屈服应力较高,开洞插管的试件由于内插钢管的屈服失效而导致整体试件屈服应力较低;CECS 28:90规范对承载力的规定与试验值较为接近,DL/T 5085—1999规范对承载力的规定安全系数最高;偏心受压和开洞插管均会导致钢管混凝土柱承载力降低,降幅分别达22%和15%。
In order to investigate the influence of the initial eccentricity of large-size concrete-filled steel tubular columns and the initial defects of open-ended cannula on its bearing capacity, taking the main arch rib Φ1 200 × 24 mm steel tube of a concrete-filled steel tubular arch bridge as the prototype and using 1: 2.4, 1: 4.8 Two kinds of geometrical scale were respectively fabricated. The axial compressive and biasing tests were carried out on CFST columns with aspect ratio of 3:1. The results of bearing capacity test were compared with those of the relevant codes in China. The results show that the experimental values of the concrete filled steel tubular columns are all larger than those of the standard calculation. The axial compressive bearing capacity of the large-size specimen and the small-size specimen have little difference with the standard, but the yield stress of the large- The results of CECS 28:90 standard on the bearing capacity are close to the test values, and the test of DL / T 5085-1999 on the bearing capacity The highest safety factor is stipulated. Both eccentric compression and open-hole cannulation will reduce the bearing capacity of CFST columns by 22% and 15% respectively.