NUMERICAL SIMULATION OF PERUVIAN RC WALL BUILDINGS USING AN EFFICIENT BEAM-BASED MODEL

In countries of high seismicity, such as Peru and Chile, the typical medium-to high-story buildings use reinforced concrete (RC) walls as their lateral load-resisting system owing to an overall satisfactory behaviour in previous seismic events. The advent of performance-based methods for seismic design of buildings demands nonlinear structural models that are efficient, reliable, and easy to calibrate. In the case of RC wall structures, such models have to consider the prominent flexure-shear interaction of wall members. This study employs an efficient beam-based computational model considering flexure-shear interaction to simulate the seismic response of three prototype RC wall structures representative of modern Peruvian buildings. These structures' geometrical, reinforcement and loading conditions were determined by analyzing a database of 20 buildings constructed in Peru between 2010 and 2022. The wall computational model, developed in OpenSees, uses fibre-based beam-column elements to simulate the flexural response and a zero-length element connected in series for the shear response. Uniaxial concrete and steel laws are combined with appropriate regularization and fatigue criteria to reproduce flexural failures due to concrete crushing and bar fracture. Shear deformations and failure are modelled using a phenomenological trilinear shear force-deformation model in the zero-length element, which is affected by the flexure demands to consider flexure-shear interaction effects. Nonlinear analyses of the wall structures were conducted with the proposed modelling approach. The research aims to study the typical failure of RC wall buildings, their displacement capacity, and the displacement and shear force demands. The nonlinear evaluation shows that displacement capacity averages 11.2‰ total drift. A primary failure mode corresponds to concrete crushing of walls by flexural deformation because of their highest axial load and lower confinement zones. The rare earthquake demands an average of 8.4‰ total drift in the flexible direction of the buildings, and the average amplification over the shear design force is 3.1 in both directions.