型钢混凝土异形柱框架地震损伤机理及灾变控制研究

Steel reinforced concrete frame with special-shaped columns, as a new structure system, is put forward based on the combination of steel reinforced concrete structure, which has excellent seismic performance, and special-shaped column structure, which is well applicable to the building function. In this project, seismic damage mechanism and disaster control of steel reinforced concrete frame with special-shaped columns will be studied. Through the earthquake simulation shaking table test of steel reinforced concrete frame with special-shaped columns, nonlinear finite element simulation with high precision and theoretical analysis, the spatial mechanical performance of the structure will be studied and the dynamic property and earthquake response will be analyzed. The seismic damage characteristic of steel reinforced concrete frame with special-shaped columns will be studied. The relationship of member damage, local structure damage and integral structure damage will be revealed and the integral damage calculated model will be established, which can reflect the migration and evolution law from member damage to local structure damage and to integral structure damage. The collapse mechanism of steel reinforced concrete frame with special-shaped columns will be studied. Based on disaster-reduction mode, the optimization design model will be established to improve the failure mode and achieve the disaster control of the structure under strong earthquake. Based on the above-study, the performance level as well as the corresponding failure criterions and quantization index of steel reinforced concrete frame with special-shaped columns will be put forward and the based-performance seismic design method will be proposed. This study will solve key scientific problems, which are present in the research field of steel reinforced concrete column structure, and may help to promote the application of the new structure to the practical engineering.

型钢混凝土异形柱框架是由抗震性能优越的型钢混凝土结构和使用功能良好的异形柱结构结合而成的一种新型结构体系，本项目拟对其地震损伤机理及灾变控制开展研究。通过型钢混凝土异形柱框架空间模型的地震模拟振动台试验及高精度非线性有限元模拟和理论分析，研究结构的空间受力性能，分析结构的动力特性和地震响应全过程；研究型钢混凝土异形柱框架的地震损伤特征，揭示构件损伤、结构局部损伤和整体损伤三者之间的关系，建立能够反映三者迁移演化规律的整体结构地震损伤计算模型；研究型钢混凝土异形柱框架的倒塌破坏机制，提出基于分灾模式的结构优化设计模型，改善结构的破坏模式，实现强震作用下结构的灾变控制。在此基础上，确定型钢混凝土异形柱框架的性能水平及其对应的失效判别标准和量化指标，提出结构基于地震损伤性能的抗震设计方法。通过本项目研究，解决型钢混凝土异形柱结构研究的关键科学问题，对于推动该新型结构的实际工程应用具有重要意义。

型钢混凝土异形柱结构体系是在异形柱结构和型钢混凝土结构的基础上发展形成的新型结构体系，不仅具有异形柱结构柱楞在室内不凸出、建筑观瞻好、房间“得房率”高等优点，而且具有型钢混凝土结构承载能力高、抗震性能好等优越性。目前对于型钢混凝土异形柱及其框架节点的研究较为全面，并取得了较多成果，而对于型钢混凝土异形柱框架的研究才刚刚开始，仅针对型钢混凝土异形柱平面框架进行了拟静力试验，这显然不能完全真实地表达和再现结构的受力情况，尤其不能反映实际地震作用下型钢混凝土异形柱框架的空间受力性能和损伤破坏过程，相应的理论分析也不够深入，并且由于缺乏合理的抗震设计方法，该新型结构不能更好地推广应用于实际工程。基于此，本课题主要开展了以下的研究工作：. （1）完成了10个型钢混凝土异形柱的水平加载试验，得到了不同加载制度下构件的水平荷载-位移曲线、骨架曲线、强度衰减与刚度退化规律、变形与滞回耗能能力，从损伤的角度对构件的破坏过程进行了分析和总结，建立了构件的恢复力模型。进而采用Opensees对试验构件进行了数值模拟，获得了柱端的弯矩-曲率滞回曲线。. （2）通过考虑循环加载次数与位移幅值对极限变形、极限承载力的影响，建立了由最大变形和累积耗能组合的型钢混凝土异形柱双参数非线性损伤模型。. （3）完成了一个五层三榀两跨实腹式型钢混凝土异形柱框架空间模型的地震模拟振动台试验，分析了结构的动力特性和空间力学性能，以及各烈度下的加速度反应、位移反应、楼层剪力、型钢及钢筋应变，并采用Opensees对试验模型进行了数值模拟。. （4）将型钢混凝土异形柱框架的性能水平划分为正常使用、暂时使用、修复后使用、生命安全和接近倒塌五档，提出了型钢混凝土异形柱框架的抗震性能目标和对应五个性能水平的层间位移角限值。进而将基于位移的抗震设计理论应用于型钢混凝土异形柱框架，结合其结构特点给出了设计步骤。. 本课题发表学术论文11篇，培养博士生2名，硕士生6名。