钢筋混凝土梁斜截面受剪承载力统一计算公式的研究

Study of unified formula for clculting shear strength of reinforced concrete beams' inclined cross-section

我国现行GB 50010-2002《混凝土结构设计规范》集中荷载与均布荷载作用下的钢筋混凝土梁斜截面受剪承载力计算公式中,关于剪跨比的不同考虑给设计人员带来诸多不便,且2种计算公式的配箍率差异较大.针对以上问题,本文分析了影响钢筋混凝土梁斜截面受剪承载力的主要因素,对已搜集到的国内外钢筋混凝土梁斜截面受剪承载力的试验资料,运用数理统计的方法,优选主要参数,同时参考国内外混凝土结构设计规范的相关规定,提出了钢筋混凝土梁斜截面受剪承载力的统一计算公式,并利用结构可靠度分析中的一次二阶矩法计算了建议公式的可靠指标.可靠度分析结果表明,建议公式的可靠指标满足GB 50068-2001《建筑结构可靠度设计统一标准》的要求,可供规范修订时参考.

According to the Design Code of Concrete Structures(GB 50010-2002),shear strength of RC beams is calculated by using two different formulas based on two different loading models,which brings much inconvenience to designers and possible great difference of stirrup ratio.This paper analyse main factors affecting shear strength of RC beams' inclined cross-section.By collecting experimental data of shear of inclined section of RC beams at home and abroad and using mathematical statistics method,a unified formula for shear strength of RC beams is proposed;reliability index of recommended formula is calculated by first-order second-moment method in structural reliability analysis.Analysis results show that the reliability index of recommended formula meets the requirement of 'Unified Standard of Reliability Design of Building Structure'(GB 50068-2001).The results can be for referenc in the current Chinese concrete stuctural design code revision.