“Comparative Study of Seismic Behavior of RCC Buliding Frames With and Without Masonry Infll Wall”

Abstract

This project investigates the seismic performance of Reinforced Cement Concrete (RCC) building frames with and without masonry infill walls. In conventional structural design, masonry infill walls are generally treated as non-structural elements; however, they significantly influence the stiffness, strength, and overall seismic response of buildings during earthquakes. A fifteen-storey RCC building located in Seismic Zone III is modelled and analysed using ETABS software. Different building configurations, including bare frames, unfilled frames, irregular-shaped frames (C-shape and T-shape), and soft-storey structures, are considered. Masonry infill walls are modelled using the Equivalent Diagonal Strut Method, and the strut widths are determined using Mainstone and Hendry formulations. Seismic analysis is carried out using the Equivalent Static Method and Response Spectrum Method in accordance with IS 1893:2016 provisions. The structural response is evaluated in terms of storey displacement, inter-storey drift, base shear, storey stiffness, and fundamental time period. The results indicate that the inclusion of masonry infill walls considerably increases the lateral stiffness and strength of the structure, leading to a significant reduction in storey displacement and inter-storey drift. In filled frames exhibit better seismic performance compared to bare frames, while soft-storey configurations show increased vulnerability under earthquake loading. The study concludes that masonry infill walls play an important role in enhancing the seismic resistance of RCC buildings and should be considered appropriately in structural analysis and design.