基于试验数据和理论的混凝土无腹筋梁斜截面承载力计算研究

Study on calculation of bearing capacity of oblique section of concrete beams without web reinforcement based on experimental data and theory

针对相关文献提出的当纵筋率较小且剪跨比较大的构件,规范公式安全储备较小甚至不足的情况,首先对我国规范抗剪计算公式的由来进行了梳理,然后对规范公式基于的试验数据库进行了统计分析,最后采用拉压杆理论推导出一个抗剪承载力计算公式。基于试验数据和理论验证了相关文献的结论;得出了规范公式在计算纵筋率较小的梁抗剪承载力的安全储备比计算纵筋率较大的梁要低,在计算剪跨比较大的梁的抗剪承载力的安全储备比计算剪跨比较小的梁要低;提出了在抗剪公式中,纵筋配筋率对抗剪承载力影响明显,应显式表达。

According to the related papers,the safety reserve of the standard formula is small or even insufficient when the longitudinal reinforcement ratio is small and the shear span ratio is relatively large.Firstly,the origin of the shear calculation formula in China′s code was sorted out,and then the statistical analysis of the code formula based on the experimental database was carried out.Finally,a shear bearing capacity calculation formula was deduced by using the strut-and-tie theory.Based on the experimental data and theory,the conclusions of relevant literatures were verified.It is concluded that the safety reserve for calculating the shear capacity of beams with lower longitudinal reinforcement ratio is lower than that of beams with larger longitudinal reinforcement ratio,and the safety reserve for calculating the shear capacity of beams with larger shear span ratio is lower than that of beams with smaller shear span ratio.In the shear formula,the ratio of longitudinal reinforcement has obvious influence on shear capacity,which should be expressed explicitly.