面向远洋岛礁的装配式复合配筋混凝土柱基本性能研究

In a previous NSFC project (51408126), we have demonstrated the innovation and particularity aspects of the hybrid reinforced precast concrete (HRPC) columns and how important it may be in serving the needs of our current national marine development strategy. To have a comprehensive understanding of HRPC columns’ behaviors and mechanical properties, the first step in this project is to study how a certain key parameters/characteristics of the hybrid reinforcement design (such as bar diameter, bonding materials, and the configuration of anchorage device, etc.) affect the performance of HRPC columns. Next, the damage evolution mechanism in columns confined by steel wire-FRP (fiber reinforced polymer) spiral stirrup when subjected to uniformly- or eccentrically-distributed compressive pressure will be investigated through laboratorial tests. An ultimate bearing capacity assessment method and a stress-strain model will then be established, considering the buckling of longitudinal bar and the interaction between longitudinal bar and compound stirrup. Afterwards, a series of HRPC column specimens will be tested in laboratory under different quasi-static loadings to establish the damage accumulation model for various column damage control techniques, including efficient reinforcement methods with large diameters or clusters, interface processing, different postyield stiffness ratios, high ductility concrete at plastic hinge area and etc. Finally, shake table tests and nonlinear time history analyses of several precast concrete columns when subjected to near-field, pulse-like strong ground motions will be performed. In summary, built upon the findings of previous research, the proposed project aims to develop a damage control method for HRPC columns reinforced with steel-FRP composites constructed on reef in the ocean environment. A performance-based seismic design method for HRPC columns will also be devised.

切合国家海洋战略需求，基于上一基金（51408126）研究成果，指出研究装配式全复合配筋增强砼柱基本性能的必要性、特殊性和创新性。具体为：首先系统研究装配式连接中的锚具构造/黏结材料/筋材直径和强度等关键参数对复合配筋连接性能的影响机理和关键技术；其次研究钢丝-FRP复合螺旋箍筋约束砼短柱在轴压/偏压加载下的损伤演化模型，建立能够考虑考虑纵筋屈曲及其与复合箍筋相互作用机理的约束砼应力应变关系模型和极限承载力评估方法；然后通过不同加载制度的拟静力试验建立可考虑大直径/集束等装配式高效配筋方式、界面处理/二次刚度比/塑性铰区高延性砼等砼柱损伤控制技术的装配式复合配筋砼柱累积损伤模型；最后，开展含脉冲的近场强地震波激励下的装配式砼柱振动台试验和非线性精细化时程分析，结合上一基金成果，提出面向远洋岛礁的装配式复合配筋砼柱损伤控制方法和基于震后性能的抗震设计方法。

本项目切合国家海洋战略需求，在高质量工厂化生产的SFCB及其锚具的基础之上，对装配式复合配筋增强混凝土柱的基本性能进行了研究。首先针对灌浆套筒连接BFRP筋及SFCB的界面性能进行了试验和理论分析，提出了筋材在锚具内的黏结滑移本构；针对集束复合筋/环境介质界面性能开展了拉拔试验和理论分析，研究了考虑黏结强度折减系数的集束复合筋/混凝土黏结滑移本构；然后，针对SFCB往复拉压和复合箍筋混凝土柱约束性能进行了试验和理论分析，提出了SBFHS约束混凝土的应力-应变模型和考虑箍筋与纵筋相互作用的SFCB受压应力-应变模型；继而开展了变化黏结长度的SFCB混凝土梁抗弯性能试验研究，研究了开裂点、屈服点、峰值点及塑性铰区应变分布特征。进行了考虑界面性能控制的SFCB混凝土柱滞回性能试验和理论研究，研究了骨架曲线、滞回耗能、变形能力及塑性铰区应变分布特征，对界面性能控制下的SFCB混凝土柱损伤进行了评价。在振动台试验数据基础上，结合数值模拟验证了装配式SFCB混凝土柱损伤可控的可行性和有效性，提出了初步的抗震设计流程。在本项目的研究基础上，项目负责人获得了与本研究有继承关系的国家自然科学基金面向项目资助，将开展近场强震下装配式不锈钢-BFRP筋混凝土柱的损伤控制机理与设计方法。