中心楼梯参与整体框架结构计算的地震反应分析

现行的设计和PKPM程序均未考虑到楼梯参与整体框架结构的计算，但5．12汶川地震和4．14玉树地震表明楼梯间的破坏均很严重。利用有限性分析软件SAP2000建立了楼梯布置在几何中心的模型和无楼梯对比模型的框架结构。计算结果表明，考虑楼梯后：楼层位移减小，Y方向（顺着楼梯斜板方向）的刚度大于X（垂直楼梯斜板方向）方向刚度；楼梯间的框架柱的轴力增大了2．6倍，剪力X／Y方向增大了1．6／3倍，弯矩XIY方向增大了1．1／1．6倍；楼梯问梯柱轴力、剪力、弯矩是对比模型相应最大内力的0．71，0．73，0．3倍，说明按构造设计的梯柱也是抵抗地震的薄弱环节，尤其是轴力和剪力。针对楼梯间框架柱和梯柱的加强设计给出了建议。

Analysis and Calculation of Whole Frame Structure with Centre Staircase during Earthquake

The staircase room has caused great damages during Wenchuan and Yushu earthquake because of present design code and PKPM program only consider the whole structure without staircase. The paper used SAP2000 and built one frame model that staircase lied in centre of structure and comparison frame model without staircase. Through the models result, we find the displacement decreases, the stiffness of Y direction （ parallel direction of staircase） is greater than X direction （ vertical direction of staircase） ; the force, shear（ X direction/direction）, moment （ X direction/Ydirection） of columns among staircase room increases to 2.6, 1.5/3,1.1/1.6 times respectively as compared with M - 1 model; the force, shear, moment of constructinal columns among staircase is O. 71,0.73,0.3 times smaller than the maximum corresponding internal force of M - 1 model, it demonstrates constructinal columns are weak link to resist earthquake, especially axial force and shear. In the last it gives some advice about the design of columns among staircase room.