火灾后钢管混凝土叠合柱工作机理和修复措施研究

There are more researches and applications of concrete-filled steel tube reinforced concrete columns for their small cross-section, high bearing capacity, high seismic resistance, superior fire resistance and convenient construction. However, most of these analyses for their working mechnism and mechanical behaviour are at room temperature, and less are after exposure to fire. In view of this, the applicant intends to combine the actual project to establish the bond-slip model between concrete filled steel tube and reinforced concrete and the computational model of the whole process analysis to the concrete filled steel tube reinforced concrete column under axial compression, pure bending, compression-bending and cyclic loading after exposure to fire. A series of typical tests will be performed to verify the finite element model. The detailed analyses of the influence of important parameters including fire temperature and fire duration to their working mechanism and mechanical essence will be investigated. On the basis of experimental study and theoretical analysis, the practical calculation methods of the bearing capacity under different loads, the restoring force model of moment-curvature and load-displacement under cyclic load and the assessment methods and repair measures of concrete filled steel tube reinforced concrete column after exposure to fire will be presented. It is expected to form the corresponding design rules so that they can provide a reference for real buildings and design regulations.

钢管混凝土叠合柱具有截面小、承载力高、抗震性能好、耐火性能优越、施工便利等优点，已进行较多研究和应用，然而多是针对常温下其工作机理和力学性能的分析，火灾后的较少。鉴于此，申请人拟结合实际工程建立火灾后钢管混凝土叠合柱钢管混凝土和钢筋混凝土之间的粘结滑移模型，火灾后钢管混凝土叠合柱轴压、纯弯、压弯及往复荷载作用下全过程分析的计算模型，并通过典型试验进行验证；采用验证过的有限元模型，细致剖析其在各种荷载作用下的工作机理和力学实质，分析受火温度、受火时间等重要参数对其工作机理的影响规律。在试验研究和理论分析的基础上，提出火灾后钢管混凝土叠合柱在各种荷载作用下承载力实用计算方法和往复荷载作用下弯矩-曲率和荷载-位移恢复力模型，并给出火灾后钢管混凝土叠合柱评估方法及修复措施，形成相关设计条文，以期为有关工程应用和设计规程的制订提供参考。

钢管混凝土叠合柱具有截面小、承载力高、抗震性能好、耐火性能优越、施工便利等优点，已进行较多研究和应用，然而多是针对常温下其工作机理和力学性能的分析，火灾后的较少。鉴于此，申请人结合实际工程建立了火灾后钢管混凝土叠合柱钢管混凝土和钢筋混凝土之间的粘结滑移模型，火灾后钢管混凝土叠合柱轴压、纯弯、压弯及往复荷载作用下全过程分析的计算模型，并通过典型试验进行验证；采用验证过的有限元模型，细致剖析其在各种荷载作用下的工作机理和力学实质，分析受火温度、受火时间等重要参数对其工作机理的影响规律。在试验研究和理论分析的基础上，提出了火灾后钢管混凝土叠合柱在各种荷载作用下承载力实用计算方法和往复荷载作用下弯矩—曲率和荷载—位移恢复力模型，并给出火灾后钢管混凝土叠合柱评估方法及修复措施，形成了相关设计条文，以期为有关工程应用和设计规程的制订提供参考。