施工期震损混凝土框架结构的服役性能研究

If some structures during construction period were suffered from earthquake, the earthquake disaster not only will affect the construction safety, but also the earthquake disaster will become a potential hazards of structural service period and greatly reduce the ability of resisting natural disasters of the structure during service period. Field investigation, experimental research, theoretical analysis and numerical simulation are combined as the research methods, the project selects the reinforced concrete frame structure damaged seismically during construction period as the research object, and confirms its service performance evaluation as the research goal, and studies the damage characteristics and the characteristics distribution rules of reinforced concrete frame structure damaged seismically during construction period, and explores its bearing performance and durability during service period. Considering different component types, from three levels of material, component and structure, the seismic damage characteristics and its distribution rules of concrete frame structure under different construction condition will be studied. The influence mechanism and degradation rules of the mechanical properties of concrete, the bonding properties of concrete and reinforcing steel bar, the bearing performance of different component, the load transfer mechanism of structure node, the bearing performance of RC frame structure caused by earthquake damaged during construction period will be studied, and considering early earthquake damage the corresponding calculation models will be established. The influence of early seismic damage on the concrete carbonation development rule and the chloride ion transport mechanism will be revealed, and the carbonation depth prediction model and chloride ion transport model considering early seismic damage will be established. This project can provide a reliable theoretical basis and technical support for evaluating and ensuring the service performance of the concrete structures with earthquake damage during construction period.

建筑结构施工期遭遇地震除了影响施工安全，还会成为结构服役期的隐患，大大降低建筑物服役期抵抗灾害作用的能力。本项目以施工期震损钢筋混凝土框架结构为对象，以施工期震损混凝土结构的服役性能评定为目标，结合现场调查、试验研究、理论分析与数值模拟等研究方法，围绕施工期混凝土框架结构的震损特征及其分布规律、服役期的承载性能与耐久性能开展系统研究。考虑不同的构件类型，从材料、构件、结构层次研究不同施工状态下混凝土框架结构的震损特征及其分布规律；研究早期震损对服役期混凝土材料的力学性能、混凝土与钢筋间的黏结性能、构件的承载性能、节点的传力机制、框架结构承载性能的影响机理与劣化规律，并考虑早期地震损伤建立相应的计算模型；揭示早期震损对混凝土碳化发展规律和氯离子传输机制的影响，建立考虑早期震损的碳化深度预测模型和氯离子传输模型。本项目研究可为评定和保证施工期震损混凝土结构服役性能提供可靠的理论依据和技术支撑。

建筑结构施工期遭遇地震除了影响施工安全，还会成为结构服役期的隐患，大大降低建筑物服役期抵抗灾害作用的能力。在项目实施期限内，分别开展了施工期混凝土受压应力-应变本构关系、施工期混凝土与钢筋间黏结性能试验研究、施工期钢筋混凝土构件端部约束简化分析研究、锈蚀扣件式钢管脚手架体系承载性能研究、施工期混凝土应力损伤的自愈性能研究等方面的研究。通过一系列的研究，建立了施工期混凝土重复荷载作用下的应力-应变本构关系模型，提出了单调、反复荷载作用下施工期混凝土与钢筋间的黏结-滑移本构关系模型，分别建立了锈蚀钢管-扣件节点的弯矩-转角关系模型和荷载-滑移关系模型、锈蚀钢管轴向稳定性的计算模型、锈蚀脚手架承载性能的计算模型。优选出了实际工程应用方便、物理力学概念清楚、可敏感反映整个损伤阈值的混凝土应力损伤评价指标；研究了早期损伤混凝土的内部损伤规律，分析了损伤程度、损伤龄期、强度等级对自愈合规律的影响。研究了施工期梁端、柱端约束随龄期的时变规律；开展了早期震损混凝土材料、与钢筋的粘结性能、构件承载性能、耐久性能的试验研究；建立了施工期混凝土框架结构的有限元分析模型，分析了施工期混凝土结构的震损特征分布规律。已基本按计划完成了各年度的研究工作，取得了有价值的理论分析结论和试验结果，而且为后续研究奠定了坚实的基础，取得了预期的效果。本项目研究成果可为评定和保证施工期震损混凝土结构服役性能提供可靠的理论依据和技术支撑。.研究期内，已发表论文20篇、收录论文2篇、在审论文2篇，其中SCI收录论文7篇、EI收录论文4篇。已培养硕士生7名，正培养博士生1名、硕士生4人，参加了重要国内或国际学术交流活动4次；获批国家自然科学基金面上项目1项；获工程建设科学技术奖科技进步二等奖1项（排名第2）、陕西省科技进步一等奖1项（排名第5）、陕西高等学校科学技术奖一等奖1项（排名第5）。