考虑扭转耦联的大底盘非对称多塔楼建筑振动分析的振型数选取

Mode Number Selection for Vibration Analysis of an Unmirrored Multi-tower Building with Enlarged Base

结合工程计算实例 ,指出非对称高层建筑存在着平移和扭转振动 ,应采用CQC法进行振型组合。大底盘上非对称多塔楼在振动中存在相对独立性 ,当塔楼之间的刚度和质量分布相差较大时 ,振型与对称多塔楼结构存在着显著差别 ,对每栋塔楼均应选取足够的振型数 ,并提出了一种选取适当振型数的判定方法。

The calculation result of 2 high residential buildings is presented.It shows that for a non mirrored building,the fundamental mode shape has x,y translation,as well as torsion components.As a method of model combination,CQC should be used.The vibration of non mirrored multi towers high building with enlarged base is independent at most time.When the distribution of each tower's mass and rigidity has a great difference,mode shapes differ greatly with that of a mirrored multi tower high building,vibration mode number for each tower should be chosen adequately in aseismic analysis.Method of choosing a proper vibration mode number for this kind of structure is concluded.