Avaliação de forças sísmicas: uma análise comparativa entre o método de forças horizontais equivalentes da NBR 15421 e o método simplificado

Abstract

This study analyzes the seismic forces applied to a reinforced concrete structure using the spatial frame of the TQS calculation model IV, focusing on the evaluation of the forces through the SAP 2000 software. This study compares the forces generated by seismic activity using the methods specified in NBR 15421: MFHE, Simplified Method, and Spectral Analysis. The analysis takes into account the regions influenced by the updated characteristic horizontal seismic acceleration map in Brazil, according to the 2023 update of NBR 15421. The study also examines the impact of soil type on the force considerations in the MFHE, concluding that soft soils significantly amplify the equivalent forces compared to rigid soils. The results indicate that the MFHE generates higher forces than the Simplified Method and that the Spectral Analysis presents results similar to the Simplified Method for a horizontal acceleration of 0.05g.