Comparative study on seismic performance of reinforced concrete buildings of different plan irregularities: Fid-Bau Portal

Comparative study on seismic performance of reinforced concrete buildings of different plan irregularities

Saif, Nusaiba Binte / Hasan, Sibgat Mehedi / Arpon, Asif Iqbal

Dhaka is one of the most seismic vulnerable regions in Bangladesh. Before constructing any building in this area, it has to be made sure that the building is earthquake resistant. The ability of resistance is highly dependent on the shape and structural system of the building. The objective of the study is to conduct an analysis on different regular and irregular shaped reinforced building considering the same dimension for each beam, column and slab following Bangladesh National Building Code (BNBC), 2020. Ten storied (G+9) building structures of six different shapes have been analyzed by using ETABS 2016 program for Dhaka (seismic zone 2). Out of these six different shapes, two are of regular plans (square & rectangle). Rest of the four shapes are with plan irregularity (W-shape, T-shape, L-shape & I-shape). Plan irregularities, vertical irregularities, storey displacement, storey drift and storey shear have been inspected for all models. Results show that in most cases, the buildings with irregularities have larger value of storey displacement and storey drift. The highest value for storey drift and displacement come for L and W shape model while the least value come for Rectangle shape model. On the other hand, storey shear changes little for irregular buildings. Besides, irregular buildings tend to fail more than buildings of regular shape. L shape model have not been able to pass the criteria of sway limitation, storey drift and torsion irregularity. W shape model has also crossed the sway limitation threshold. Shear walls have been introduced to the buildings who fail to make these buildings resistant towards earthquake. Results show that shear walls reduce the value of aforementioned three parameters. This research can be useful for the construction of buildings with different shapes and irregularities to take proper measurements for safety in Dhaka City.