抗侧刚度比对底框砌体房屋抗震性能的影响

摘要

底框砌体房屋由于底部空间的灵活性广泛应用于临街建筑中,但此类结构在历次地震中破坏严重.特别是当刚度分布不当时易引起薄弱层转移,发生过渡层先于底层的破坏.本文以底框砌体结构房屋为研究对象,建立了4种不同抗侧刚度比底框砌体结构房屋有限元模型,通过大震作用下的结构弹塑性时程分析,得到了结构变形规律,探究了过渡层破坏机理和薄弱层转移原因,并在此基础上对抗侧刚度比值下限值提出了建议.研究结果将为此类房屋的结构设计和加固改造提供技术参考.%Due to the flexibility of space applications of the bottom,bottom frame masonry buildings are widely used in street construction,but such a structure is severely damaged in the previous earthquake.Especially when lateral stiffness is misallocated,the weak layer transfer is easily caused which will lead to the transition layer damage before the bottom.In this paper,the houses of bottom frame masonry structure are taken as the research object,and four kinds of finite element models with different lateral stiffness ratios are established.Through structural elastic-plastic time history analysis under the great earthquake,the deformation law for structure is obtained,and the failure mechanism of transition layer and weak layer tansfer are discussed.On this basis,suggestions of lower limit value of lateral stiffness ratio are put forward.The results of study will provide technical references for this kind of buildings in structural design and retrofiring.