Seismic Analysis of Multi-storied RC Building with Soft Storey Floating Column at Different Level

Many multistoried buildings are constructed as open ground storey as unavoidable feature in residential as well as commercial buildings. A soft storey is also known as a weak storey or stilt storey. It is a storey in a building that has substantially less stiffness value than the stories above or below. It also has inadequate shear resistance and ductility to resist the earthquake forces. The Masonry infill walls are commonly used in the structure and considered as a non-structural element. The stiffness contribution of infill walls can be considered in analysis by equivalent strut, however it is observed that most of the buildings in urban areas are constructed with open first storey as an important functional requirement for parking of vehicle or reception lobbies. The soft storey has inadequate lateral load resistance due to its reduced stiffness. This study also involves the study of effect of infill wall in comparison with the bare frame in the analysis. Mainly the study focuses on the comparison in between brick infill and light weight infill material. A parametric study is performed on the example building with soft storey at different level and it is intended to describe the performance characteristics such as deformation, stiffness, time period, bending moment and drift. The project aims to highlight the consideration of open storey in the analysis and subsequently finding the measures to reduce the effect of soft storey. Equivalent static analysis and Response spectrum analysis is performed for the models of building using ETABS software