多层砖房底部两层框架抗震变形性能分析

Seismic Deformation Behavior of a Two-story Frame at the Bottom of a Multistory Masonry Building

为实现多层砖房底部两层框架结构的加固,需要研究其抗震变形性能。以某底部两层框架、上部四层砖房建筑为对象,通过STRAND7有限元软件构建有限元计算模型,考虑水平荷载与垂直荷载,深入分析多层砖房底部两层框架抗震变形性能。仿真结果表明,建筑结构振型受结构横向楼板刚度的影响较显著,不同振型的频率变化中,X向1阶频率与Y向2阶频率变化最快,楼板平面内弯曲频率变化最慢;整体结构在X向与Y向分别呈现线性剪切变形和弯剪变形,Y向上由于填充墙发挥抗震墙功能,底部两层框架变形较小;在7度多遇地震影响下,底部两层结构中第二层楼板变形较第一层严重,多层砖房底部两层框架建筑结构处于弹性工作状态。

To strengthen the bottom two stories of a multistory masonry frame structure,it is necessary to study its seismic deformation performance.Taking a masonry building with a bottom twostory frame and an upper fourstory frame as the object,a finite element calculation model was constructed with finite element software STRAND7.Considering the horizontal and vertical loads,the seismic deformation performance of the twostory frame at the bottom of the multistory masonry building was analyzed.Simulation results showed that the vibration mode of the building structure was significantly affected by the lateral floor stiffness.The changes of the first mode frequency in the X direction and second mode frequency in the Y direction were the fastest,and the bending frequency in the floor plane changed the slowest.The whole structure showed a linear shear deformation in the X direction and a flexureshear deformation in the Y direction,due to the filled wall in the Y direction assuming the function of seismic wall.Deformation of the bottom twostory frame was small;under the influence of a 7degree earthquake,deformation of the second story of the bottom twostory structure was more serious than that of the first story,and the twostory frame structure at the bottom of the multistory masonry house was in an elastic working state.