MULTICOMPONENT SEISMIC ASSESSMENT OF A 16-STORY RC BUILDING IN ALMATY USING EUROCODE 8

Abstract

This study presents a numerical assessment of a 16-story cast-in-place concrete building in Almaty, Kazakhstan, under static and multi-component seismic actions in accordance with SP RK EN 1998-1:2004/2012 and SP RK 2.03-30-2017. A finite-element model was developed in LIRA-SAPR for a wall structural system with coupled shear walls on type IB soils. The analysis explicitly accounts for both horizontal and vertical earthquake components; modal responses are combined using the SRSS or CQC methods, considering more than 20 vibration modes along the X, Y, and Z axes (a_g = 0.487 g; a_vg = 0.438 g). The cumulative modal participation masses reach 89.8% in X and Y, indicating adequate capture of the dynamic response. Maximum interstory drifts are 5.5 mm (X) and 6.3 mm (Y), and roof displacements are 75 mm and 85 mm, respectively – within the relevant code limits. The building satisfies stability and seismic-resistance criteria; for structures higher than 12 stories in a 9-intensity seismic zone, the necessity of Special Technical Conditions (STU) is confirmed. The novelty lies in a practice-oriented implementation of Eurocode provisions adapted to Kazakhstan, with explicit treatment of the vertical component and multi-component spectral analysis, improving demand estimates and the applicability of results to high-rise design in seismically active regions.