Impact of lateral load on torsional behavior of building in hilly region using SAP2000

Abstract

Buildings on slopes are particularly vulnerable due to their lower lateral load capacity. These types of buildings are asymmetrical and have irregular configurations. The height of the columns varies, resulting in the eccentricity of the structure because the centre of mass and centre of stiffness do not coincide. This irregularity leads to torsional behavior and gives us the need to analyze these buildings in terms of their basic conditions and their behavior when the floor plan configuration is changed. In this paper, torsion is calculated, which is an effective parameter to determine the behavior of the building. In this study, an RCC building with G+3 floors and floor slopes of 15o, 26o, and 40o with a change in aspect ratio was considered for the analysis and tested for the vulnerability and suitability of the configurations against lateral loads. Further, bare frame building is modelled with the addition of bracing throughout the height of the building. The assumed angle section is equal angle ISA 150 x 150 x 12 mm. Modelling of bracing was done in three types; bracing in both plan directions, bracing only in one ridge direction (Y-Z axis) and bracing only in one valley direction (X-Z axis). These were analyzed on the slope of 26˚ with a change in aspect ratio and tested for the vulnerability and suitability of the configurations against lateral loads. SAP2000 was used to analyze buildings on slopes, changing the aspect ratio, slope of the site, and effect of adding bracing. Results shows that global bracings have minimum displacement and rotation compared to bracing in Y-Z axis, X-Z axis or without bracings for all aspect ratio considered in this study.