| 侧向冲击荷载下钢筋混凝土墩柱的性能 |
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| 作者姓名： | 赵武超 钱江 |
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| 作者单位： | 同济大学土木工程与防灾国家重点实验室，上海 200092 |
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| 基金项目： | 国家自然科学基金资助项目51438010 |
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| 摘 要： | 采用数值仿真技术建立了足尺钢筋混凝土墩柱精细有限元模型, 分析了侧向冲击荷载下墩柱的动态响应和抗冲击性能, 提出了一种基于截面损伤因子的损伤评估方法, 讨论了不同碰撞参数对钢筋混凝土墩柱破坏模式和损伤机理的影响.结果表明: 冲击荷载下钢筋混凝土墩柱的耗能主要分为接触区域局部耗能和构件整体耗能; 当冲击体的初始动能恒定时, 冲击质量和冲击速度的不同组合会导致钢筋混凝土墩柱损伤破坏机理的显著差异; 基于截面损伤因子的损伤评估方法可以比较准确地描述墩柱的破坏状态.轴压力对墩柱抗撞能力的有利贡献比较有限, 且墩柱随着轴力的增大更易发生剪切破坏; 冲头刚度对碰撞力和墩柱动态响应的影响十分显著.
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| 关 键 词： | 钢筋混凝土墩柱 冲击荷载 损伤评估 能量耗散 破坏机理 |
| 收稿时间： | 2018-02-28 |
Performance of reinforced concrete pier columns subjected to lateral impact |
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| Affiliation: | State Key Laboratory of Disaster Risk Reduction in Civil Engineering, Tongji University, Shanghai 200092, China |
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| Abstract: | Anti-impact design is a very important aspect to ensure the safety of reinforced concrete (RC) bridges against extreme loads, such as explosions from terrorists attacks and accidental collisions of rockfalls and vehicles. The impact behavior of the pier columns, which is the most important vertical components in the bridge structures, have attracted much attention in recent years, and experimental studies on the impact behavior of scaled pier columns have been conducted by many researchers. It has been acknowledged that the size effect has a significant influence on the dynamic response of structural elements. Therefore, in this study, the performance of the prototype reinforced concrete pier columns under lateral impact loads was investigated. Using a numerical simulation technique, three-dimensional finite element models of a prototype pier column under impact loading were established and validated through comparisons with impact tests in the literature. A new damage assessment method based on the sectional damage factor was presented to determine the damage level of reinforced concrete pier columns. The effects of impact parameters such as impact mass, impact velocity, and impact stiffness on the failure mode and damage mechanism of reinforced concrete pier columns were also identified in detail. The simulation results show that the energy dissipation of reinforced concrete pier columns under impact loading can be divided into local energy dissipation in the contact area and overall energy dissipation in the whole component. When the initial kinetic energy of the impact body remains constant, different combinations of the impact mass and velocity can lead to a significant discrepancy in the damage mechanism of reinforced concrete pier columns. The proposed damage assessment method based on sectional damage factors can be utilized to accurately describe the failure state of the reinforced concrete pier columns. In addition, the contribution of the axial load to the impact capacity of reinforced concrete pier columns is limited, and the columns are more likely to suffer shear failure with the increasing axial force. The impact stiffness has a significant effect on the impact force and the dynamic response of reinforced concrete pier columns. |
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