底部两层框架砖房抗震性能分析

AN ANALYSIS ON THE ANTI SEISMIC BEHAVIOR OF MASONRY BUILDING WITH FRAME STRUCTURE AT LOWER TWO STORIES

采用多自由度层间剪切模型，对底部两层框架砖房１／６ 比例模型和原型结构进行了动力特性计算和弹塑性地震反应分析，并与１／６ 比例模型的振动台试验结果进行了对比分析。结果表明，经过合理设计的底部两层框架砖房具有较大的抗震能力和良好的抗震性能，可以应用于７、８ 度抗震设防区。如果适当提高第１ ～３ 层的抗震强度，并加强其抗震构造措施，可望应用于９ 度区。第１ 层和第２ 层是这种结构体系的薄弱层，且框架柱端，尤其柱脚为薄弱部位，第３ 层与第２ 层的侧移刚度比，在７、８ 度时宜分别控制在１－２～２－０ 和１－２ ～１－６ 范围内。底部两层框架砖房的变形属剪切型，地震力沿楼层高度近似呈倒三角形分布。

The dynamic Characteristics and elasto plastic seismic response on 1/6 scale model as well as its prototype of masonry building with frame structure at lower two stories are theoretically calculated and analysed by storey shear model with multi degree of freedom,and the results above are compared with the results of shaking table experiment of 1/6 scale model. It is shown that the anti seismic capacity and the anti seismic behavior of this kind of structure which is reasonably designed are excellent,and it can be applied in the zones with seismic design intensity of 7 or 8 degree. If the anti seismic strength and the anti seismic construction of its 1 to 3 story are suitably improved,it may be applied in the zones of 9 degree.The first story of the structure is weak,and when 7,8 degree,the reasonable ratio of stiffness for second story to first story is 1.2～2.0 and 1.2～1.6. The deformation belongs to shear model,and the form of seismic force is nabla,so that,the horizonatally seismic force of the structure can be calculated by bottom shear method.