某高层建筑立面呈琵琶塔造型,结构形式为混凝土-钢结构混合结构,琵琶中线为混凝土剪力墙筒体,四周曲柱是截面为箱形的钢柱,其结构高宽比严重超限。本文使用ANSYS软件,采用时程分析法从两类动力稳定的角度对其抗震性能进行了研究。第一类稳定是基于Lyapunov运动稳定性定义的弹性动力屈曲问题,通过时间冻结法即动态特征值方法进行研究;第二类稳定本质上是动力极值问题,采用逐步增大地震荷载幅值求解结构稳定临界荷载的方法进行研究。计算结果表明,该建筑动力稳定性能较差,某些部位的杆件需要加强。该方法给建筑结构的稳定性分析提供了新的思路,可供不规则复杂结构体系设计时参考。
The facade of one high rise building is designed as Pipa tower, which used steel-concrete composite structure. The middle part of Pipa tower is concrete shear wall tube, and around columns are steel columns with box-section. The height width ratio of this bulding is severe out-of-codes. By means of ANSYS program two kinds of dynamic stabilities excited by earthquake of this building are studied by the method of time history response analysis. The first definition of dynamic stability is essentially dynamic buckling based on the definition of Lyapunov, which is analyzed by a modified time freezing method and dynamic eigenvalue method; the second one is the problem of dynamic ultimate load carrying capacity, which is obtained by combing Incremental Dynamic Analysis (IDA) with Budiansky & Roth (B-R) criteria. Results show that this building is of a poor performance of dynamic stability, some parts must be reinforced. Therefore, the presented method can supply a reliable and feasible computing approach for the stability analysis of such super tall and complex buildings.