The Impact of Vertical Seismic Component on Concrete Structures: Analysis and Design according to the Algerian Seismic Code (RPA 2024)

Abstract

This study examines the effect of vertical seismic components on Reinforced Concrete (RC) structures, specifically in the framework of the new Algerian seismic code (RPA 2024). Despite developments in the knowledge of horizontal ground motions, recent earthquakes, such as those in Turkey-Syria (2023) and Algeria (Béjaïa 2021-2022, Boumerdès 2003), have highlighted the significant contribution of vertical accelerations in amplifying structural damage. The current research evaluates low-rise (2-story), mid-rise (6-story), and high-rise (9-story) buildings under seven earthquake records scaled according to RPA 2024 specifications. Using nonlinear dynamic analysis, it advances current knowledge by providing insights into the specific effects of vertical ground motion on the evaluation of variations in internal forces, lateral displacements, and story-level responses, focusing on height-dependent effects, force redistribution, and displacement amplification factors. The results indicate that low-rise buildings (2-story) have negligible effects from combined Horizontal and Vertical (H+V) loading with variations of 5-15%, and mid-rise buildings (6-story) have moderate effects (20-30%). In contrast, high-rise buildings (9 stories) have significant height-dependent variations of 10-35%.