民国钢筋混凝土结构中的梁构件计算方法研究

Research on structural calculation methods for beam members of modern Chinese reinforced concrete buildings

为研究民国时期混凝土梁构件的设计计算方法,从材料层面到构件层面,对民国时期混凝土设计与结构计算的相关历史文献进行研究,总结出民国时期混凝土梁构件的设计与计算方法,并结合案例分析,与现代混凝土梁构件的设计计算方法进行比较研究,包括钢筋混凝土梁的受弯承载力计算方法及受剪承载力计算方法。通过对比计算分析,不考虑地震荷载作用时,在1.0%~2.0%纵筋配筋率的范围内,采用现行规范计算的受弯承载力是采用民国规范计算的受弯承载力的3.6~4.0倍;在配箍率0.1%~1.0%范围内,采用现行规范计算的受剪承载力是采用民国规范计算的受剪承载力的1.6~2.4倍;在弯起钢筋配筋率0.5%~1.5%范围内,采用现行规范计算的受剪承载力是采用民国规范计算的受剪承载力的2.0~2.4倍。研究结果可为民国钢筋混凝土梁的结构安全评估提供科学依据。

In this study,we reviewed historical literature on modern Chinese reinforced concrete structures in order to find appropriate structural calculation methods for such structures built from 1912 to 1949.After obtaining the original structural calculation methods for beams of modern Chinese reinforced concrete buildings,we also carried out a comparative study using the original and the contemporary calculation methods,including the methods for calculation of flexural capacity and shear capacity of concrete beams.According to the comparative calculation analysis,without considering earthquake load,when the longitudinal reinforcement ratio is 1%-2%,the calculation values of flexural capacity in the current codes are 3.61-4.02 times those in the earlier codes;when the stirrup ratio is 0.1%-1%,the calculation values of shear capacity in the current codes are 1.61-2.41 times those in the previous codes;when the bent-up reinforcement ratio is 0.5%-1.5%,the calculation values of shear capacity in the current codes are 2.03-2.36 times those in the previous codes.