基于损伤的钢筋混凝土箱型墩双向恢复力模型  

Damage-based Biaxial Restoring Force Model of Reinforced Concrete Box Piers

作　　者：夏樟华[1] 宗周红[2] 夏坚[1] 薛万善 林元铮 

机构地区：[1]福州大学土木工程学院,福建福州350116 [2]东南大学土木工程学院,江苏南京210096

出　　处：《中国公路学报》2017年第12期60-70,109,共12页China Journal of Highway and Transport

基　　金：国家自然科学基金项目(51408360;51678141);西南交通大学陆地交通地质灾害防治技术国家工程实验室开放基金项目(SWJTU-GGS-2014001)

摘　　要：为得到水平双向荷载耦合作用引起的累积损伤对钢筋混凝土箱型墩滞回特性、强度和刚度退化的影响规律,对其双向恢复力特性进行研究。首先,介绍了以长细比、轴压比、体积配箍率和加载角度为参数的钢筋混凝土箱型墩双向拟静力试验、有限元参数分析以及考虑水平双向荷载耦合作用的损伤因子计算公式。其次,将试件的骨架曲线简化为带下降段的三线型折线,建立钢筋混凝土箱型墩骨架曲线特征点及其刚度的计算方法。最后,根据实测滞回曲线的特点,分析损伤因子与钢筋混凝土箱型墩柱强度和刚度退化之间的关系,提出水平双向荷载作用下从峰值位移卸载的荷载陡降段的计算公式,同时给出双向滞回规则,建立钢筋混凝土箱型墩柱基于损伤的双向恢复力模型。研究结果表明:依据建议的钢筋混凝土箱型墩恢复力模型计算得到的骨架曲线、滞回曲线与拟静力试验结果吻合较好,最大误差不超过10%,且可以较好地体现出双向荷载作用引起的箱型墩损伤加剧效应以及滞回特征,可以为钢筋混凝土箱型墩结构的多维弹塑性抗震性能分析提供理论参考。In order to get the influence rule of the cumulative damage caused by the horizontal bilateral load coupling effect on the hysteretic behavior, strength and stiffness degradation of the reinforced concrete （RC） box pier, the biaxial restoring force model of the RC box pier was investigated. Firstly, the biaxial pseudo static test and finite element simulation of the RC box pier, considering axial load ratio, slenderness ratio, reinforcement ratio and loading angle, were conducted, and the calculation formula of the damage factor considering the bidirectional coupling load effect was also presented. Secondly, the skeleton curves of the testing piers were idealized as a three-line type model with the descending segment, and the calculation method of the skeleton curve and the corresponding stiffness for the RC box pier were established. Finally, the relation between the damage factor and the strength and stiffness degradation of the specimens were analyzed according to the characteristics of the experimental hysteretic curves, whilst the calculation formula of the load-steep-descending factor from the unloading point of the peak displacement was proposed. At the same time, the biaxial hysteresis rules of the box pier was given, and the damage-based biaxial restoring force model for the RC box pier was established. The results show that the calculating skeleton and hysteresis curves from the proposed restoring force model of the RC box piers agree well with results of the quasi-static testing, and the maximum error is less than 10%. The proposed model reflects the damage aggravated effects and hysteresis characteristics caused by horizontal bi-directional loading, so it will provide the theoretical reference for the multi-dimensional seismic analysis and design for the RC box pier.

关 键 词：桥梁工程 钢筋混凝土箱型墩 双向拟静力试验 双向恢复力模型 损伤因子 滞回曲线 

分 类 号：U443.22[建筑科学—桥梁与隧道工程]