楼梯对不同刚度钢筋混凝土框架结构地震反应的影响

Analysis on Seismic-response of Different Stiffness Reinforced Concrete Frame Structure with Staircase

为研究楼梯对结构地震反应的影响,利用ETABS设计了2个不含楼梯的钢筋混凝土框架模型和2个包含楼梯的具有不同初始抗侧刚度的钢筋混凝土框架模型,采用振型分解反应谱法对模型进行了弹性地震反应对比计算分析。结果显示:楼梯参与结构整体计算后,结构的抗侧刚度、振动模态、结构基底剪力及梯间框架柱内力分配比例等均明显变化,且影响程度因原框架抗侧刚度大小不同而异。建议当前框架结构设计可以适当提高结构抗侧刚度,以减小楼梯对结构地震反应的改变程度,降低考虑楼梯参与结构整体抗震分析计算的复杂性。

Four computer models of reinfored concrete frame structure with or without staircase were made,seismic-performance of the models were calculated by adopting spectrum analysis method based on ETABS.The results show that including staircase into models will change the story-stiffness distribution,vibration mode,shear-ratio of staircase-frame column of frame structure significantly,the effects are different depenning on the different stiffness of the original frame structure.The paper proposes that the stiffness of the original frame structure should be enhanced firstly in seismic design of reinfored concrete frame structure with staircase at present.