装配式高强钢组合延性桁框结构抗震性能研究

In order to solve the scientific problems about less types and “fat beams and columns” of prefabricated steel construction systems, the prefabricated special truss moment frame fabricated with high-strength steel (HSS-PSTMF) is purposed. The HSS-PSTMFs consist of truss beams with links and concrete-filled high strength steel tubes (CFHSSTs), and the beam-column joint is ConXR form. The HSS-PSTMFs with high assembly efficiency have greater lateral stiffness and good energy dissipation performance. The truss beams can provide long spans in two dimensions, and is easy for pipelines installed. The CFHSSTs with good economic performance can decrease cross-section, hide in the walls and increase usable areas. The engineering applications of HSS-PSTMFs were limited, because of the insufficient research on its seismic performance. Taking HSS-PSTMFs as the study subject, the project intends to conduct research on its seismic properties by means of the experimental, finite element and theoretical analysis. The failure mechanism, energy dissipation properties and the influence of the main parameters to the lateral stiffness, load-bearing capacity, ductility, energy dissipation of HSS-PSTMFs are researched. Furthermore, the deformation coordination mechanism between link and steel frame is explicated, and the ideal failure mode of HSS-PSTMF based on optimal energy dissipation is researched. And then, the elastic-plastic lateral story shear distributions of HSS-PSTMFs during earthquakes are proposed. Moreover, the performance-based seismic design methods and construction measures of HSS-PSTMFs are purposed. The results will offer theory basis and technical support for the extensive application of HSS-PSTMFs.

针对我国多高层装配式钢结构建筑结构体系少、“肥梁胖柱”等问题，提出装配式高强钢组合延性桁框结构，由设置耗能段的桁架梁及高强钢管混凝土柱构成，梁柱节点采用ConXR连接，刚度大、耗能强、装配效率高。桁架梁有效增加二维空间跨度，便于装修管线布置；高强钢管混凝土柱有效减小柱截面，可藏柱于墙，增大使用面积，经济性能好，但目前对该结构抗震性能研究不足，限制了其工程应用。本项目拟以装配式高强钢组合延性桁框结构为研究对象，通过拟静力试验、数值分析和理论推导等手段，研究该结构在地震作用下的耗能机制和破坏机理；探讨主要参数对结构刚度、承载力、延性和耗能性能的影响规律；明确耗能段与钢框架的协同工作机制，建立结构最优耗能的理想失效模式，揭示该结构在不同抗震性能水准时的地震作用分布规律，提出该结构基于性能的抗震设计方法、设计指标和构造建议。研究成果可为该结构体系的设计和施工提供理论依据和技术支持，推动其工程应用。

项目以装配式高强钢组合延性桁框结构为研究对象，重点研究了结构受力机理及抗震性能，分析了耗能段长度、钢材组合、节间数量、长深比等关键参数对结构抗震性能的影响。研究结果表明：结构不仅具有较高的承载力和抗侧刚度，还具有较好的延性及耗能性能；建议耗能段取值范围为0.1至0.5倍跨度之间；耗能段节间数量对结构受力影响不大，可根据耗能段长度和长深比的限值进行设计，在满足结构安全性要求的前提下，可以将结构的长深比提高到3；耗能段钢材可以优先采用LY225、Q235，非耗能段钢材取Q460、Q690钢材时均能保持体系优良的抗震性能。项目建立了结构双折线的恢复力模型，给出了其简化分析方法；提出了考虑柱脚刚度影响时耗能段取值建议公式；此外项目充分考虑竖腹杆影响，修正了美国《钢结构抗震设计规范》中的现有耗能段抗剪承载力公式，本项目研究成果可为我国《延性桁框结构技术规程》的编制提供参考。