高强钢筋增强UHPC-NC组合桥墩塑性铰长度  

Plastic Hinge Length of UHPC-NC Hybrid Pier Reinforced by High-strength Steel Bars

作　　者：任亮[1,2] 刘青云 方博文 温帅 REN Liang;LIU Qingyun;FANG Bowen;WEN Shuai(School of Civil Engineering and Architecture,East China Jiaotong University,Nanchang 330013,China;State Key Laboratory of Performance Monitoring Protecting of Rail Transit Infrastructure,East China Jiaotong University,Nanchang 330013,China)

机构地区：[1]华东交通大学土木建筑学院,江西南昌330013 [2]华东交通大学轨道交通基础设施性能监测与保障国家重点实验室,江西南昌330013

出　　处：《郑州大学学报（工学版）》2023年第6期119-126,共8页Journal of Zhengzhou University（Engineering Science）

基　　金：国家自然科学基金资助项目(52068024);江西省自然科学基金资助项目(20224BAB204055);江西省重点研发计划一般项目(20202BBG73035)。

摘　　要：为探讨高强钢筋增强UHPC-NC组合桥墩塑性变形能力,应用大型有限元程序ABAQUS,结合Mander本构模型、双折线本构模型、UHPC材料本构关系和混凝土损伤塑性模型,建立了高强钢筋增强UHPC-NC组合桥墩延性分析模型,通过与不同UHPC加固高度的钢筋混凝土桥墩和不同加载角度下UHPC箱型桥墩拟静力试验结果对比验证了模型的有效性。在此基础上,进一步提出塑性铰区域长度确定方法,探讨轴压比、纵筋直径、纵筋屈服强度以及试件高度等参数对组合桥墩塑性铰区域长度的影响规律,评估规范塑性铰长度建议公式的适用性,建立了UHPC-NC组合桥墩等效塑性铰长度计算公式。结果表明:组合桥墩塑性铰区域长度随轴压比增大单调递减,随试件高度的增大单调递增,随纵筋直径和屈服强度的增大表现出先增大后减小的变化趋势;当轴压比接近0.5时,UHPC的破坏与受拉区纵筋的屈服同步发生,当纵筋直径和屈服强度分别为16 mm、500 MPa时,墩底塑性铰区域耗能能力达到最优。与数值分析结果的对比进一步表明:规范建议的计算公式在一定程度上将低估组合桥墩的塑性变形能力,建立的等效塑性铰回归公式可为高强钢筋增强UHPC-NC组合桥墩抗震研究提供参考。To discuss the plastic deformation ability of UHPC-NC hybrid pier reinforced by high-strength steel bars,a ductility analysis model was established and calibrated by the corresponding pseudo-static test of concrete piers strengthened with different UHPC reinforcement heights and UHPC box piers with different loading angles,with the involving in the constitutive model of Mander and double line,the constitutive relationship of UHPC material and the damage plastic model of concrete in the finite element program ABAQUS.Based on the validation of the test results,the method on determining the length of the plastic zone was proposed,and the parameter analysis varying in the axial compression ratio,the diameter and yield strength of the longitudinal reinforcement,and the height of the specimen was conducted.On the basis of the applicability of the proposed formula in the evaluating code,the formula for calculating the equivalent plastic hinge length of hybrid pier was established.The results showed that,the length of plastic zone for UHPC-NC hybrid pier reinforced by high-strength steel bars would decrease with the increase of axial compression ratio,increased firstly and then decreased with the diameter of the longitudinal reinforcement and longitudinal reinforcement yield strength,and increased with the increase of the specimen height.When the axial compression ratio was close to 0.5,the failure of UHPC occurred simultaneously with the yield of longitudinal bars in the tensile zone.When the longitudinal reinforcement diameter and yield strength were 16 mm and 500 MPa,the energy dissipation capacity of the plastic zone reached the optimum.By comparing with the numerical analysis results,it was further shown that the empirical formulas underestimated the plastic deformation ability of UHPC-NC hybrid pier.The established equivalent plastic hinge regression formula could provide a reference for the seismic research of UHPC-NC hybrid pier reinforced by high-strength steel bars.

关 键 词：塑性变形能力 UHPC-NC组合桥墩 ABAQUS 高强钢筋 塑性铰长度 延性分析模型 

分 类 号：TU377[建筑科学—结构工程] U24[交通运输工程—道路与铁道工程]