抗震框架梁受拉钢筋最小配筋率的功能和取值

Function and Limiting Value of Minimum Ratio of Reinforcement for Tension Reinforcement in Seismic Frame Beams

钢筋混凝土抗震框架梁的端部是保证结构抗震延性和塑性耗能能力的关键部位。本文以梁端截面的开裂弯矩与屈服弯矩的关系为基础,分析了梁端正、负弯矩受拉钢筋最小配筋率在保证框架抗震性能中的作用。通过与有关国家规范最小配筋率相应规定的对比,对我国修订后规范抗震框架梁受拉钢筋最小配筋率的取值方案进行了分析评价,并给出了进一步改进的建议。

The ends of reinforced concrete beam in seismic frame are critical positions that ensure ductility and plastic energy dissipation capability of the structure. Based on the relation between cracking moment and yield moment of beam end section, the functions of minimum ratios of reinforcement for tension reinforcement of the beam end in positive and negative moment areas in ensuring seismic behavior of the structure are studied in this paper. Through comparing these ratios with those used in other countries, the scheme for the limiting value of the minimum ratio of reinforcement, adopted in revised design code of China, is evaluated and some suggestions are put forward.