Seismic analysis of multistoreyed building and retrofitting using different bracing systems

Multi-storeyed buildings and tall structures are subjected to lateral loads due to earthquake. These loads cause the failure of structures if buildings are not designed according to seismic standards. To avoid such failures due to up-gradation of seismic zones or additions to buildings, retrofitting is adopted to increase the strength of existing buildings. Bracing systems are suitable for tall structures. This paper presents experimental and numerical studies conducted on a scaled-down three-dimensional model fabricated with and without bracings. The acceleration versus time graph results of the experimental studies is compared with the results of ABAQUS. FEM model is updated to match time history responses of acceleration in the two analyses. Experimental dynamic analysis is carried out with the help of a shake table apparatus. The model is connected to accelerometers ADXL345 on each floor and these accelerometers are connected to the Arduino Uno board. Numerical experiments were conducted for different configurations of braces. The ABAQUS results show that displacement is reduced by 72.9 percent, 75.8 percent for diagonal bracing and X bracing in alternate floors, 79.5 percent and 80.8 percent for diagonal bracing and X bracing in all floors. Non-destructive tests are conducted on an existing multi-storeyed building at MSRUAS to obtain existing strength parameters and were implemented in the model of the building. The building is analyzed with and without bracings and displacements are compared. It was found that displacements reduced with an increase in base shear.