Comparative Dynamic Analysis of Tsunami-Induced Loads on Regular and Irregular Reinforced Concrete Buildings in Coastal Regions

This study presented a journal-style comparative dynamic analysis of tsunami-induced loads on regular and irregular RC buildings in a coastal region. Four G+6 RC building configurations were analysed in ETABS using a combined tsunami load case consisting of hydrostatic pressure, hydrodynamic drag force, impulsive bore impact, debris impact and uplift pressure. The tsunami loading was represented using normalized time-history functions developed in Excel and imported into ETABS, and the final TS_FINAL load case was analysed using linear direct integration with the HHT method, 5% damping, 300 s duration and 0.05 s time step. The results demonstrate that tsunami response is governed by structural geometry, stiffness distribution, exposed tsunami interaction area and transient inundation behaviour. Based on the actual result tables, Plan-Irregular A developed the lowest peak overturning moment but also the highest roof displacement and storey drift. Hence, it cannot be classified as the best configuration when deformation safety is considered. Plan-Irregular B showed the lowest roof displacement and drift, along with a lower OTM than the Regular and Vertical-Irregular Buildings, making it the most favourable overall configuration in the present comparative study. The Regular Building showed satisfactory and stable behaviour due to uniform stiffness distribution. The Vertical-Irregular Building showed displacement and drift similar to the Regular Building but developed the highest overturning moment. The study confirms that realistic dynamic tsunami analysis is necessary for coastal RC structures and that plan configuration can strongly influence tsunami force interaction and deformation response.

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