DYNAMIIC RESPONSE OF FRAME-CORE WALL TALL BUILDINGS TO WIND LOAD

Abstract

Tall building comprising frames and shear walls properly coupled together is one of the most efficient and economical structural systems. The continuum approach is employed for free vibration analysis of this kind of building and the whole structure is idealized as a shear-flexural cantilever. The effect of axial deformation in frame is considered and incorporated in the formulation of the governing equations. The Bubnov-Galerkin method is used to transform the governing differential equations into a set of algebraic equations. Computer programme has been developed and numerical examples are solved. The results are compared with the values obtained from a finite element package "ETABS" and other existing methods to validate the technique. The method is simple, efficient and can be adopted as an analytical tool especially during the preliminary design stage. Based on the free vibration analysis, a method of estimating the peak displacement and peak acceleration of wind-excited buildings is presented, in which along-wind, cross-wind and torsional vibrations are considered. The expressions for along-wind responses are developed through the random vibration theory, while cross-wind and torsional responses are based on empirical information obtained from wind tunnel measurements. A step-by-step procedure and numerical examples are presented to illustrate the simplicity of this approval. As a special case, the behaviors of structure with soft story are also studied based on the proposed method.