矩形截面型钢混凝土梁抗弯极限承载力

Ultimate flexural capacity of steel reinforced concrete beams with rectangular section

采用JGJ 138—2016、СИ3-78、YB 9082—2006、AISC 360-16、叶列平公式,计算了所收集的51个矩形截面型钢混凝土(SRC)梁试件的抗弯极限承载力,并将计算结果与试验值进行比较;分析了所收集试件的参数范围及现有计算方法出现计算误差的原因,讨论了现有计算方法在计算理论等方面存在的局限性,并进行理论推导,提出了矩形截面SRC梁抗弯极限承载力计算方法;采用所提出的计算方法,计算了所收集试件的抗弯极限承载力。分析结果表明:现有计算方法的计算值与试验值均存在一些偏差;СИ3-78中的受压区高度取值不合理,且该方法的计算误差随混凝土强度提高而增大;JGJ 138—2016未考虑中性轴与型钢位置的相对关系对计算结果的影响,存在局限性;YB 9082—2006与AISC 360-16未考虑型钢与混凝土相互作用及型钢的布置方式等问题;叶列平公式计算结果较为保守;采用提出的抗弯极限承载力计算方法得到的计算值与试件试验值的比值均值为0.953,方差为0.015,计算值与试验值吻合较好;所收集SRC梁试件的含钢率为1.77%~5.77%,小于YB 9082—2006所建议的合理含钢率范围,因此,今后还需进一步开展高含钢率试件的补充试验,以便完善矩形截面SRC梁的抗弯极限承载力计算方法。

JGJ 138—2016,CИ3-78,YB 9082—2006,AISC 360-16,and YE Lie-ping's formulas were used to calculate the ultimate flexural capacities of 5l collected specimens of steel reinforced concrete(SRC)beams with rectangular sections.The calculated results were compared with the test values.The ranges of parameters of the collected specimens and the reasons for the calculation errors of the existing calculation methods were analyzed.The limitations of the existing calculation methods were discussed in terms of the calculation theory and other aspects.Theoretical derivations were performed,and a method for calculating the ultimate flexural capacities of SRC beams with rectangular sections was proposed,and the ultimate flexural capacities of the collected specimens were calculated by using the proposed method.Analysis results show that some deviations are found between the calculated values obtained by the existing calculation methods and the test values.The height value of the compression zone in CH 3-78 is not appropriate,and the calculation error of this method increases with the increase in concrete strength.The impact of the relative relationship between the neutral axis and the position of the structural steel on the calculation results is not considered in JGJ 1382016,and limitations exist.YB 9082—2006 and AISC 360-16 do not take into account the interaction between structural steel and concrete or the arrangement of the structural steel.The YE Lie-ping's formulas produce conservative results.The average ratio of the values calculated by the proposed method for the ultimate flexural capacity to the test values of specimens is 0.953,with a variance of 0.O15.The calculated values agree well with the test values.The steel ratios of the collected SRC beam specimens range from 1.77%to 5.77%,which is smaller than the reasonable steel ratio range suggested by YB 9082—2006.Therefore,it is necessary to carry out further supplementary tests of specimens with high steel ratios in the future,so as to improve the calculation method for the ultimate flexural capacity of SRC beams with rectangular sections.1tab,10 figs,31refs.