The evolution of construction techniques and the growing demand for efficient and sustainable solutions have driven the development of modular construction using precast reinforced concrete. This approach offers significant advantages over traditional construction methods, particularly in terms of reduced execution time, improved quality control, and optimized use of resources. Its application has expanded in several countries, such as Sweden, Germany, Japan, and the United States, where it is valued for its efficiency and structural performance. However, the response of these systems under dynamic actions, such as earthquakes, still requires further studies to better characterize their behavior and vulnerabilities, ensuring a safe and reliable design in future applications.
The present study aimed to investigate the influence of building height on the seismic behavior of modular precast concrete structures. To achieve this, a comparative numerical analysis was performed between two buildings with the same floor plan configuration but different heights (4 and 6 stories), assessing the impact of this variable on the overall structural response.
Initially, fundamental concepts related to modular structures were presented, including their differences from in situ construction and the relevant seismic design framework. Subsequently, the numerical modeling process and the adopted methodology were described. The seismic behavior of the four-story building was then characterized through modal, response spectrum, nonlinear pushover, and dynamic analyses. Finally, the effect of adding two additional stories was evaluated, and the results were compared for the same set of analyses.
The results indicate that increasing the number of stories led to an average reduction in stiffness of about 60% and in maximum strength of approximately 30%, while doubling the natural vibration periods. Consequently, higher displacements, bending moments, and shear forces were observed, resulting in more flexible dynamic behavior.