考虑轴压比影响时框架稳定性的刚重比控制方法

Control Method of the Stability of Frame Structures by Its Ratio of Rigidity-to-Gravity Considering the Influence of the Ratio of Axial Compressive Force to the Axial Compressive Ultimate Capacity of Section

改变框架柱的轴压比,对10根钢筋混凝土柱与5根钢柱进行压弯试验,拟合了轴压比对框架柱抗侧刚度的影响公式.用等效水平力方法推导了结构临界重力荷载,提出了基于结构刚重比控制的框架重力二阶效应的稳定计算方法,给出了考虑轴压比影响时框架结构稳定性的刚重比控制方法.结果表明:考虑轴压比影响,框架柱抗侧刚度提高,使得计算的刚重比更容易满足规范关于框架结构稳定性对刚重比的要求,考虑轴压比对框架柱抗侧刚度的影响,符合工程实际,为现行规范对高层框架侧移计算的完善提供参考.

Experiments in compression and bending with various ratios of axial compressive force to the axial were done for 10 concrete columns and 3 steel columns compressive ultimate capacity of the section, and the influence formulae of the ratio of axial compressive force to the axial compressive ultimate capacity of the section on the sideway stiffness of the frame columns were drawn out. The critical gravity load of the structure was derived by the equivalent horizontal load method, and the calculation method about the stability of the frames, which considered the effect of the second order of gravity by controlling the ratio of rigidity-to-gravity of the structure, was presented. It has been shown that the sideway stiffness of the frame columns increased when considering the influence of the axial load on the sideway stiffness of the frame columns, which made the ratio of rigidity-to- gravity meet the demand of the stability of the frame structures. Taking into account the influence of the axial load on the sideway stiffness of the frame columns can agree with engineering practice and can be helpful to the revision of the existing design codes for calculating the sideways of frames.