论文部分内容阅读
运用数值计算方法对钢筋混凝土(RC)圆柱破坏时截面受弯承载力极限值进行计算,计算时考虑了箍筋对混凝土的约束效应和纵筋应力强化效应。计算结果显示截面受弯承载力极限值比规范规定的理论值有较大增加,特别是在轴压较高、箍筋约束效果明显时。截面受压区高度计算是RC圆柱截面受弯承载力计算的关键。圆柱破坏时截面受压区高度主要受轴压比、配箍特征值和纵筋配筋特征值三个参数影响。根据数值计算的结果进行回归,提出了受压区对应圆心角απ计算方法。在此基础上通过理论分析并结合95个大比例试件试验结果,提出截面受弯承载力极限值计算方法,计算结果与试验结果吻合很好。参数分析的结果表明在轴压比为0.6时截面受弯承载力极限值比规范公式计算值能提高60%左右,这一显著的弯矩强化效应值得在设计中引起重视。
The limit values of flexural bearing capacity of RC columns under cyclic failure are calculated by numerical calculation. The restraining effect of stirrups on concrete and longitudinal reinforcement effect are considered in the calculation. The calculated results show that the ultimate value of flexural capacity of section has a greater increase than the theoretical value specified in the code, especially when the axial compression is high and the stirrup restraint effect is obvious. The calculation of the section compression zone height is the key to calculate the RC column section flexural capacity. The height of the compression zone of the section when the column is damaged is mainly affected by the three parameters of the axial compression ratio, the characteristic value of the hoop and the characteristic value of the longitudinal reinforcement. According to the result of numerical calculation, regression is made and the calculation method of the corresponding central angle απ of compression zone is put forward. On this basis, theoretical analysis and 95 test results of large proportion specimens are put forward to calculate the ultimate bearing capacity of section, and the calculation results are in good agreement with the experimental results. The results of parametric analysis show that the limit value of flexural capacity of section is about 60% higher than that of the standard formula at the axial compression ratio of 0.6. This remarkable moment strengthening effect deserves attention in the design.