装配式混凝土双柱桥墩抗震性能试验与理论研究

Prefabricated concrete double-column piers, which have advantage in accelerating construction and good structural performance, energy saving and environmental protection, is an extensively used construction system in low seismic zones. However, the behavior and complex performance in connection of precast segmental bridge columns and the absence of system research and design method limit the application of the fabricated double-column bridge pier construction in moderate to high seismic regions. Focusing on the mechanical characters and damage behavior of fabricated double-column bridge pier, the main contents will be carried out as follows: (1) The detailed connection scheme of prefabricated concrete double-column piers with flag-shaped hysteretic behavior will be proposed and the restoring force model of the piers subjected to bidirectional horizontal load will be established. The optimum design of energy dissipation, ductility seismic performance and re-centering capacity will be performed. Based the bi-axial quasi-static tests, the section analysis program of bi-axial moment-curvature, which not satisfying the plane section assumption, will be developed, and the restoring force model and the equivalent plastic hinge length calculation formula of the piers subjected to bidirectional horizontal load will be established. (2) The damage mechanism and energy dissipation of double-column bridge pier under strong earthquake will be studied. Through the shaking table test, the collision effect, residual drift and failure modes of the fabricated double-column bridge pier will be studied. Combined with the result of experiment, the comprehensive analytical model at both local and global levels of fabricated double-column pier with nonlinear finite element method will be developed. (3) With the vulnerability analysis, the seismic fortification levels and performance criteria will be determined. Then, the performance-based seismic design procedure for prefabricated concrete double-column piers will be established.

装配式混凝土桥墩具有施工快、质量优和节能环保等优点，在国内外低抗震烈度区获得了广泛应用。但装配式双柱墩的拼装连接部位受力复杂，至今仍缺乏系统的研究及相应的设计方法，使其在中、高度抗震烈度设防区的的应用受到了一定的限制。本课题拟针对装配式双柱墩的抗震性能开展以下研究：①提出具有旗帜型耗能的双柱式预制拼装桥墩连接构造形式并进行双轴弯曲恢复力模型研究。对耗能、延性和自复位能力等性能进行优化，通过双向拟静力试验方法，编制不满足平截面假定的双轴弯曲截面分析程序，进行双轴弯曲恢复力模型和等效塑性铰长度计算公式研究；②强震下装配式混凝土双柱桥墩损伤耗能及其破坏机理研究。通过振动台试验方法，研究新型装配式双柱桥墩连接构造的碰撞效应、残余位移、破坏模式，建立精确的装配式双柱墩的局部和整体分析数值模型；③进行装配式双柱桥墩易损性分析，确定设防水准与性能目标，建立基于性能的装配式混凝土双柱墩的抗震设计方法。

预制装配技术具有节能，环保，快速文明施工的特点。以双柱桥墩拼装方案为对象，对多种预制拼装连接方案包括预应力筋，灌浆套筒，灌浆波纹管，机械套筒等构造的拼装方式进行了试验研究和理论分析，建议了装配式双柱墩合理连接构造形式并给出设计方法。①旗帜型耗能可通过预应力筋和局部塑性铰区形状记忆合金钢筋来实现，研究不同轴压比、不同普通钢筋配筋率、不同预应力筋配筋率对墩柱承载能力的影响，提出了双轴受力验算公式；②通过双向拟静力试验探索装配式混凝土双柱桥墩在双向水平地震作用下的损伤机理，建立了双轴弯曲损伤恢复力分析模型；③通过双向输入振动台试验方式，研究不同频谱特性地震动输入下的损伤状态以及相应的损伤控制指标；④通过对大悬臂盖梁拼装接缝的剪切和弯曲能力大比例尺试验，研究了不同拼接构造的拼装盖梁的破坏模式和承载能力计算方法；⑤通过部分工程实践，初步建立了装配式桥墩抗震设计方法。该技术具有较强的工程应用前景，符合建筑工业化发展的方向，为装配式桥梁的发展提供了较好的参考。