Comparative Study on Structural Design and Cost Analysis of Low-Rise Public Building Designed as per IS 1893:2016 and Withdrawn IS 1893:2025 Seismic Provisions

Abstract: The Bureau of Indian Standards (BIS) has issued IS 1893:2025 with major revisions to revise the seismic hazard assessment, zoning and design provisions for earthquake resistant structures. But the code was withdrawn soon after its publication and IS 1893:2016 still remains the prevailing seismic design code in India. Although withdrawn, the assessment of the engineering implications of the proposed provisions provides valuable insight to the potential impact of future revisions to Indian seismic design practice.

The present work is an attempt to compare the structural and economical aspects of G+2 with Mumty railway station building designed as per IS 1893:2016 and withdrawn IS 1893:2025 provisions. The building at Devprayag, Uttarakhand, India was modelled and analysed in ETABS with the same geometry, material properties, loading conditions and design assumptions excepting the seismic parameters prescribed by the two codes. The comparison was done based on design base shear, storey displacement, storey drift, reinforcement requirement & construction cost.

The results show that the seismic provisions of IS 1893:2025 would increase the design base shear by about 2.25 times, maximum storey displacement at Mumty level by 2.147 times and maximum storey drift by 2.187 times compared to IS 1893:2016. The average reinforcement requirement was increased by 24.9% for beams and 49.5% for columns, leading to an increase in the total structural cost of about 27%. The study shows that the provisions, which were withdrawn, lead to a considerably more conservative design with higher seismic resistance and simultaneously cause a significant increase in the amount of material used and the construction cost. The results provide valuable technical information for structural engineers, researchers and code development authorities on the practical implications of proposed amendments to seismic design standards for low rise public buildings.

Keywords: IS 1893:2016; IS 1893:2025; Seismic Design; Reinforced Concrete Building; Structural Analysis; Construction Cost Assessment; Earthquake-Resistant Design, Railway Station Building.