增设抗震墙加固单跨框架时刚度特征值的讨论

Discussion on stiffness characteristic coefficient of single-bay framestructure strengthened with shear wall

为了研究增设抗震墙加固既有单跨框架时需设墙体的合理数量,以单跨框架的层数及刚度特征值为参数,采用解析方法,讨论了加固前后原框架地震剪力变化.结果表明:在选取最优刚度特征值的情况下,当总层数n=4时,原框架结构第4层抗剪承载力缺口为3.4%～4.4%;当总层数n=8时,原框架结构第8层抗剪承载力缺口为11.7%～12.8%;当总层数n=12时,原框架结构第12层抗剪承载力缺口为14.4%～15.7%、第11层抗剪承载力缺口为4.3%～5.2%.由此可得,原框架顶部楼层进行加固不可避免、原框架总层数越多顶部需加固的楼层数越多且相应楼层框架抗剪承载力缺口越大、最优刚度特征值为1.0～1.2等.

Aiming at studying the reasonable number of shear walls utilized to strengthen single-bay frame structure, the storey number and stiffness characteristic coefficient of the structure are selected as parameters to investigate the variation of the frame shear force before and after being reinforced. The results show that, with the optimal stiffness characteristic coefficient, if the storey number n = 4, the shear capacity of the 4th floor lacks 3.4% to 4.4% ; if n = 8, the shear capacity of the 8th floor lacks 11.7% to 12.8% ; if n = 12, the shear capacity of the 12th floor lacks 14.4% to 15.7%, and that of the llth floor lacks 4.3% to 5.2%. Therefore, the upper floor of the single- bay structure needs strengthening inevitably. The number of stories need reinforcing and the shear capacity gap of the upper floor increase with the increase of the storey number of the structure. The optimal stiffness characteristic coefficient is 1.0 to 1.2.