Seismic Analysis of Medium Rise Multi-Storey RCC Frame with and without Vertical Irregularity

It's a very big challenge that building or structure must withstand lateral forces such as earthquake and wind load. Irregular buildings constitute a large portion of the modern urban infrastructure. Structures are never perfectly regular and hence the designers routinely need to evaluate the likely degree of irregularity and the effect of this irregularity on a structure during an earthquake. The proportional distribution of lateral forces evolved through seismic action and wind load also in each storey level due to changes in stiffness of frame on irregular frame is analyzed. The objective of the project is to carry out Response spectrum analysis (RSA) of vertically irregular RC building frames. In the present work, the comparative analysis of various structures is performed using ETABS. The main aim of the project is comparative study of the stiffness of the structure by considering the three models that is Regular Structure, structure with ground storey as the soft storey and vertical irregular structure. All these three models are analysed with static and dynamic earthquake loading. The results are tabulated and graphs are plotted for displacement, drift, base shear and time period. Based on the results and discussion the structural behaviour and stiffness is concluded for regular and irregular structures and it was found that Vertical irregular building frames experience larger base shear than similar regular building frames. The stiffness irregular building experienced lesser base shear and has larger inter storey drifts. The storey shear force was found to be maximum for the first storey and it decreased to a minimum in the top storey in all cases.