弹性地基上空间巨型框架结构的简化振动分析

对软土地基上的超高层建筑空间巨型框架的振动分析建立了一种新的简化分析模型,即弹性地基—空间杆系—层模型。也就是将空间巨型框架中的辅助框架柱只考虑其轴向刚度,沿巨型框架梁的轴线方向连续化后,作为巨型梁单元的文克弹性地基,把巨型梁按照文克弹性地基梁来处理,然后将巨型柱和巨型文克弹性地基梁组成空间巨型框架,在考虑了地基(半无限大弹性地基)的弹性变形后,按空间刚架进行刚度分析;将建筑物的质量集中于巨型梁的楼层,进行自由振动分析。算例计算结果表明,新的简化模型是合理的、可行的。

A SIMPLIFIED VIBRATION ANALYSIS OF LARGE SPATIAL FRAME STRUCTURES ON ELASTIC FOUNDATION

A new simplified analytical model, namely Elastic foundation-Spatial structure member-Storey model, is developed for free vibration analysis of large spatial frames of high-rise buildings built on soft soil. Only axial rigidities are considered for columns of the subsidiary frames. Large spatial frames are then idealized continuously as Winkler elastic foundation beams along the axes of the girders. A large spatial frame supported on semi-infinite elastic foundation is then decomposed into a frame with large columns and girders with a Winkler foundation beam underneath. The stiffness matrix used for the free vibration analysis is thusly obtained through the simplified frame; the masses of the frame are considered to be concentrated on its floors. Free vibration analysis is then performed. Examples show that the computing model is rational and feasible.