| Abstract: |
Tall reinforced concrete (RC) buildings must resist two dominant lateral actions, earthquake ground motion and strong wind, and the governing action depends on height, stiffness and seismic hazard. This empirical study analyses how these demands change with building height through a data-driven, code-based parametric investigation. Five RC frame-core models with 10, 15, 20, 25 and 30 storeys, each on a 24 m x 24 m plan, were analysed using the seismic provisions of IS 1893 (Part 1):2016 and the wind provisions of IS 875 (Part 3):2015. Fundamental periods, seismic coefficients, design base shear, wind base shear, overturning moments and serviceability drifts were computed and organised into five tabulated datasets. The results show that wind base shear grows from 1052 kN to 4550 kN as height increases from 10 to 30 storeys, whereas Zone V seismic base shear grows only from 2588 kN to 3406 kN because the lengthening period reduces spectral acceleration. Wind therefore governs beyond about 20 to 25 storeys in Zone V and beyond 10 to 15 storeys in Zone III. Top wind displacement rises from 0.4 mm to 45.1 mm, yet all serviceability limits are satisfied. The conclusions confirm that the governing design criterion shifts with height and that core stiffness is the key control parameter for slender towers. These findings form the basis of the design recommendations presented in the conclusion. Wind-to-seismic demand ratios are reported so that engineers can interpolate the results to intermediate heights, and the study is intended as a screening tool for preliminary design. |
