| 基于位移的整体桥混凝土桩基抗震设计准则 |
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| 引用本文： | 黄福云,单玉麟,罗小烨,陈宝春.基于位移的整体桥混凝土桩基抗震设计准则[J].中国公路学报,2021,34(5):99-109. |
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| 作者姓名： | 黄福云 单玉麟 罗小烨 陈宝春 |
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| 作者单位： | 1. 福州大学 土木工程学院, 福建 福州 350108;2. 福州大学 福建省土木工程多灾害防治重点实验室, 福建 福州 350108 |
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| 基金项目： | 国家自然科学基金项目（51578161）；福建省高校优秀人才支持计划项目（G50011504）；中国博士后科学基金项目（2020M682074） |
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| 摘 要： | 实际工程中的整体桥常采用柔性桩基础吸纳温度或地震作用下产生的水平往复变形。为研究整体桥桩基的抗震性能和变形能力等，开展多种类型桩基的拟静力试验研究，分析比较不同类型桩基的破坏模式、水平变形与承载能力、应变与弯矩分布规律等。研究结果表明：钢筋混凝土RC桩和PHC管桩的破坏位置随配筋率和预应力度的增加而加深，桩-土相互作用效果提高，能有效改善混凝土桩基的抗开裂变形性能；矩形截面较圆形截面桩具有更好的桩-土相互作用效果和耗能能力；桩基的变形拐点会随着配筋率和截面的增大而明显加深，更有利于提高桩基的有效桩长和水平变形能力；相比RC混凝土桩，H形钢桩表现出了更好的弹塑性变形能力和延性，耗能能力更强；桩基承载比可以较好地评估桩-土相互作用效应；混凝土桩基的骨架曲线可以用弹性极限位移、不可观测的开裂位移、可观测的开裂位移、压碎位移、峰值荷载位移和极限位移的特征点表述，且随着配筋率和预应力度的增加，其位移特征点均会有所提高；提出基于位移的整体桥混凝土桩基“三阶段设防、五等级破坏”抗震设计准则，可供有关规范的设计与制定提供参考。
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| 关 键 词： | 桥梁工程 整体桥 拟静力试验 不同类型桩基 桩-土相互作用 抗震设计准则 |
| 收稿时间： | 2019-11-12 |
Displacement-based Seismic Design Criteria of Concrete Piles in Integral Abutment Jointless Bridges |
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| HUANG Fu-yun,SHAN Yu-lin,LUO Xiao-ye,CHEN Bao-chun.Displacement-based Seismic Design Criteria of Concrete Piles in Integral Abutment Jointless Bridges[J].China Journal of Highway and Transport,2021,34(5):99-109. |
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| Authors: | HUANG Fu-yun SHAN Yu-lin LUO Xiao-ye CHEN Bao-chun |
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| Affiliation: | 1. School of Civil Engineering, Fuzhou University, Fuzhou 350108, Fujian, China;2. Key Lab of Fujian Province on Prevention Disaster of Civil Engineering, Fuzhou University, Fuzhou 350108, Fujian, China |
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| Abstract: | A flexural pile foundation in integral abutment jointless bridges (IAJBs) is usually used in practical engineering to absorb the horizontal reciprocating deformations induced by the effects of ambient temperature or earthquakes. Therefore, a pseudo-static test on different types of piles in IAJBs was carried out to study their seismic performance and deformation capability under low-cycle horizontal reciprocating displacement loads. The behaviors of piles, in terms of damage modes, horizontal deformations and bearing capacities, and distributions of strain and bending moment, were compared. The test results indicate that with an increase in the reinforcement ratio and pre-stressed level, the pile damage position develops downward to a larger embedded depth. The effect of soil-pile interaction and crack resistance can be enhanced by increasing the reinforcement ratio and pre-stressed level. Moreover, a rectangular pile has better pile-soil interaction and energy dissipation capacity than a circular pile. The inflection points of pile deformation will be deeper with increases in the reinforcement ratio and section size, which can increase the effective length and horizontal deformation capacity of the pile. Compared with the circular pile, the steel H-pile has a better elastic-plastic deformation capacity, ductility and energy dissipation capacity. The bearing ratio is a suitable indicator to evaluate the effect of pile-soil interaction. The test results also indicate that the skeleton curves of the concrete pile are expressed using displacement characteristic points of elastic ultimate displacement, unobservable cracking displacement, observable cracking displacement, crushing displacement, peak displacement and limiting displacement. The displacement characteristic point improves with the increase in the reinforcement ratio and pre-stressed level. Based on the skeleton curves of the concrete pile, a displacement-based seismic design criterion “three-stage seismic fortification levels and five-grade damage levels” in IAJBs is proposed, which can provide a reference for the design and formulation of existing specifications. |
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| Keywords: | bridge engineering integral abutment jointless bridges (IAJBs) pseudo-static low-cycle test different types of piles soil-pile interaction seismic design criteria |
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