Análisis de edificaciones de baja altura con elementos estructurales de acero de lámina delgada doblada en frío en zonas de alta sismicidad

Abstract

Ecuador, located within the Pacific Ring of Fire, is exposed to a high seismic threat. The city of Machala, due to its geographical location, is among the most vulnerable areas in the country. In this context, low-rise buildings constructed with cold-formed thin-gauge steel have gained prominence due to their lightness, cost-effectiveness, and ease of assembly. However, their use in areas of high seismicity poses significant challenges in terms of structural performance. The reduced thickness of the profiles used, together with the absence of specific Ecuadorian regulations for the design of this type of structure, leads to low rigidity and flexible dynamic behavior, which increases floor drifts and vibration periods, compromising stability in the face of severe seismic movements. This paper focuses on the structural analysis of a low-rise building constructed with cold-formed thin-gauge steel, located in the city of Machala. Using numerical simulation tools, the structure was modeled considering the geometric conditions, gravitational and seismic loads defined by the Ecuadorian Construction Standard (NEC). Based on the results obtained in the static and dynamic analyses, the need to implement reinforcement measures was identified. As a solution, strategically located reinforced concrete structural walls were incorporated, which significantly reduced floor drifts, decreased vibration periods, and improved the overall stiffness of the system. This resulted in more adequate structural behavior in the event of seismic events, complying with the parameters established by the regulations.