【摘要】 钢框架结构是110 kV和220 kV全室内变电站首选的结构形式。钢柱与基础的连接对于钢框架结构整体的力学行为至关重要，外包式钢柱脚具有承载力和刚度大、施工较为便捷等特点，但在弯剪作用下受力机制复杂，钢柱与外包混凝土之间的相互作用随着钢柱水平挠曲变形的发展而不断变化。进行了外包式钢柱脚的有限元建模分析，主要影响参数包括外包高度、荷载形式、轴压比等。数值模拟结果表明，提出的黏聚模型可准确模拟外包钢柱脚的力学行为，外包高度较低的柱脚在压弯作用下受压侧翼缘可发生局部屈曲，导致结构的承载力降低。外包混凝土的顶面和底面均可能出现较大的剪力。因此，仅按照规范进行顶部箍筋的加密是不够的，还需加强底部箍筋的配置。更多还原

【Abstract】 Steel frame structure is the preferred structural form for 110 kV and 220 kV indoor substations. The connection between steel columns and foundations is crucial for the mechanical behavior of steel frame structures. The steel column base wrapped with concrete exhibits high load-bearing capacity,enhanced stiffness, and construction expediency. However, the force mechanism under bending and shear action is complex, and the interaction between steel columns and wrapped concrete changes continuously with the development of horizontal bending deformation of steel columns. Finite element modeling analysis was conducted on the steel column base, with main influencing parameters including wrapped height, load form, axial compression ratio, etc. The numerical simulation results show that the proposed cohesive model can accurately simulate the mechanical behavior of the wrapped steel column base. The column base with lower wrapped height can experience local buckling of the compression flange under bending, leading to a decrease in the structural bearing capacity. The top and bottom surfaces of the wrapped concrete may experience significant shear forces. Accordingly, it is not enough to only densify the top stirrups according to the specifications, and it is also necessary to strengthen the stirrups at the bottom end.更多还原