Seismic Analysis of Step-Back Building Resting on Sloping Ground considering Different Types of Bracing System
International Journal for Modern Trends in Science and Technology, Vol. 05, Issue 07, July 2019, pp.-22-26
5 Pages Posted: 15 Aug 2019
Date Written: August 12, 2019
Buildings constructed in hilly areas pose special structural and constructional problems. Dynamic characteristics of hill buildings are different from the buildings resting on plane topography, as these are irregular and unsymmetrical in both horizontal and vertical directions. The irregular variation of stiffness and mass in vertical as well as horizontal directions, results in Centre of mass and Centre of stiffness of a storey not coinciding and not being on a vertical line for different floors. When subjected to lateral loads, these buildings result in significant torsional response. Due to site conditions, buildings on hill slope are characterized by unequal column heights which result in variation of stiffness of the columns of the same storey. The short stiff columns attract more forces and damage. The buildings resting on sloping ground mainly fails due to torsional moments which developed due to configuration of building on slope. These torsional moments may reduce by using bracing system in the buildings. In present study, Step back building with different types of bracing systems (i.e. X, V, Inverted V, Diagonal, bare frame) are considered. These models are analyzed by response spectrum analysis using ETABS v 9.0 finite element code. The dynamic parameters obtained from analysis have been discussed in terms of fundamental time periods, maximum top storey displacements, storey drifts and base shear compared within the considered configurations of hill buildings. At last, the effective type of bracing which can be used in step back building on sloping ground is found out.
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