型钢混凝土异形柱空间框架地震响应试验研究

Experimental study on seismic response of steel reinforced concrete spatial frame with special-shaped columns

为研究型钢混凝土异形柱空间框架的地震响应,首次对缩尺比为1/4的三榀两跨五层框架模型进行地震模拟振动台试验,输入El Centro波、Taft波和兰州波,分析模型的动力特性、应变响应、加速度响应、位移响应、基底剪力和滞回性能。结果表明:强震作用下,型钢混凝土异形柱框架形成典型的梁铰破坏机制,满足"强柱弱梁"的抗震设计要求;随着输入地震波加速度峰值的增大,结构累积损伤逐渐增加,自振频率逐渐降低,阻尼比增大,加速度和位移响应峰值出现时刻向后推迟;结构在进入塑性阶段的过程中发生扭转变形;基底剪力呈现出先快后慢的增长趋势;滞回曲线饱满,表现出良好的耗能能力。型钢混凝土异形柱框架能够满足强柱弱梁和大震不倒的抗震设防要求。

In order to study the seismic responses of steel reinforced concrete spatial frames with special-shaped columns, a 1/4-sealed frame model was tested on the shaking table with the E1 Centro wave, Taft wave and Lanzhou wave as inputs, respectively. The dynamic characteristics, strain responses, acceleration responses, displacement responses, base shears and the energy dissipation capacity were analyzed. The results show that under strong earthquake, the failure mode of the steel reinforced concrete frame with special-shaped columns is the beam-hinged mechanism, satisfying the seismic principle of ＂ strong column and weak beam＂ With the increase of the peak accelerations of the input seismic waves, the accumulated damage of the frame increase gradually, resulting in the decrease of the natural frequency, the increase of the damping ratio, and the delay of the peak accelerations and displacements. Torsion deformation of the frame appeared during the process from elastic stage to plastic stage. The base shears grew fast firstly and then slowly. The hysteretic curves were plump, indicating the good energy dissipation capacity of the frame. Steel reinforced concrete frame with special-shaped columns can meet the seismic requirements of strong-columns-weak-beams and no collapse under the rare earthquakes.