都市村庄底框砌体结构的动力特性分析

Dynamic Characteristic Analysis of Bottom Frame Masonry Structure in Urban Villages

以都市村庄典型底框砌体房屋为研究对象,建立有限元分析模型.利用Block Lanczos法对结构进行动力特性分析,得到了结构自振周期和振型特征.分析结果表明,沿主轴方向,结构纵向刚度弱于横向;沿楼层方向底层振动强烈,表现出"上刚下柔"的不利特性;添加抗震墙后底层没有出现局部振动过于强烈的不利现象,但是上部砌体部分反应加剧,说明了需要合理添加抗震墙以防薄弱层发生转移.研究结果可为此类房屋的建造和改造及抗震性能评价提供技术参考.

Taking the house of bottom frame masonry structure as object,we established a model of finite element. Using Block Lanczos method to analyse the dynamic characteristic we got the structural free vibration periods and modes. The analysis results show that along the major axis,the longitudinal lateral stiffness is weaker than the transverse;along the floors’direction,the bottom floor vibrates strongly,which shows“large rigidity of the upper and weak of the lower part”. After adding shear walls,the bottom floor vibration decreases,and does’t appear strongly adverse phenomenon of local vibration,however,the reaction of masonry part increases,which illustrates the need to add reasonable shear walls in case of weak layer transfer. The results of study will provide technical references for the construction and improvement of such buildings and evaluation of seismic performance of such buildings.