SEISMIC RESPONSE OF A SOFT GROUND STOREY REINFORCED CONCRETE STRUCTURE WITH DIFFERENT COLUMN ORIENTATIONS

Abstract

Open ground storey (OGS) is a typical feature in the modern construction throughout the world. Buildings having open ground storey are undesirable in seismically active areas as depicted by past earthquakes such as San Fernando 1971, Northridge 1994, Kobbe1995, Bhuj India 2001.Also the past studies have been done on open ground storeys without taking the orientation of columns into
consideration. In this study, the objective is to check the best orientation of rectangular columns in a G+8 building with open ground storey which is a Soft Storey by observing the displacements, drift and Stiffness of the various models in X and Y direction. For this purpose, six models are created having different orientation of rectangular columns viz Model CCO (corner columns oriented), Model ECO (Exterior columns oriented), Model ACO (All columns oriented), Model ECOEC (External columns oriented excluding corner ones), Model AICO(All interior columns oriented) and the displacement, drift and stiffness of these models are compared . A reference model known as Model BM is considered for the study in which the stiffness and strength of the infill wall is not taken into account. The displacement, drift and stiffness of all the five models are compared to the reference model and it is observed that Model CCO has
least difference in the displacement, drift and stiffness in X and Y direction. Hence the Model CCO is preferred.