震区中小跨径桥梁墩柱配筋率取值范围

为研究配筋率对钢筋混凝土桥梁延性抗震性能的影响，并在不同设防烈度对主筋配筋率的合理取值进行细分。以钢筋混凝土桥梁为研究对象，通过拟静力模型试验与有限元数值分析的方法，研究竖向钢筋(主筋)配筋率对桥墩延性的影响，提出典型桥墩的多级性能水平量化指标；并探究在氯离子侵蚀的恶劣环境下，不同配筋率对桥梁抗震性能所带来的影响，从而对氯离子侵蚀环境下的震区中小跨径桥梁墩柱配筋率取值范围提供参考建议。结果表明：考虑氯离子侵蚀作用下的恢复力模型能够较好地反映刚度的退化特性，墩柱的最佳配筋率取值范围为1.11%～2.72%;当加速度为0.3g(g为重力加速度)时，仅从配筋率的角度已无法满足墩柱的损伤指标，建议采用减隔震体系进行抗震设计，如采用延性体系时配筋率不得小于2.64%。研究结果可为中小跨径连续桥梁抗震设计提供参考。

Study on the range of reinforcement ratio of Piers of medium and small Span Bridges in earthquake area

In order to study the influence of reinforcement ratio on the ductile seismic performance of reinforced concrete bridges, the reasonable value of main reinforcement ratio was subdivided in different fortification intensity. Taking reinforced concrete bridge as the research object, the relationship between vertical reinforcement ratio and pier ductility was studied by means of quasi-static model test and finite element numerical analysis, and the quantitative index of multi-stage performance level of typical piers was put forward. And the influence of different reinforcement ratio on the seismic performance of bridges in the harsh environment of chloride erosion was also explored, so as to provide reference suggestions for the range of reinforcement ratio of small and medium-span bridge piers in the earthquake area under chloride erosion environment. The results show that the restoring force model under chloride erosion can better reflect the degradation characteristics of stiffness, and the range of the optimal reinforcement ratio of piers is 1.11%~2.72%. When the acceleration is 0.30g, the damage index of piers can not be satisfied only from the point of view of reinforcement ratio. It is suggested that seismic isolation system should be used for seismic design, such as ductility system, the reinforcement ratio should not be less than 2.64%. The research results can provide reference for the revision of seismic code for small and medium-span continuous bridges.