Análise técnico-orçamentária e ambiental de fundações em estacas hélice contínua e pré-moldadas para uma edificação de uso comercial

Abstract

The choice of foundation type represents a relevant stage in the development of structural projects, as it directly influences the construction, economic, and environmental aspects of the building. In this context, this study aimed to compare two deep foundation solutions, continuous flight auger piles and precast concrete piles, applied to a single-story commercial building located in the municipality of Pato Branco, Paraná, Brazil. The methodology included the characterization of the case study, the analysis of soil investigation data, and the geotechnical design of the piles using Teixeira’s method, in order to estimate the allowable load capacity of the analyzed solutions. For the pile caps, the structural design was carried out using the strut-and-tie method, considering the column loads and the pile configuration in each pile cap. Subsequently, the quantities of concrete, steel, and formwork were determined and used both in the cost estimate and in the environmental assessment through Life Cycle Assessment (LCA). The LCA was developed based on the main quantified inputs, allowing the alternatives to be compared through environmental impact categories associated with material consumption, such as global warming, mineral resource scarcity, fossil resource scarcity, and water consumption. The results showed that the two alternatives presented similar structural configurations for the pile caps, due to the building loads and the geotechnical conditions of the site. However, the precast pile solution showed a more favorable performance in the cost analysis, representing the lowest-cost alternative for the case studied. From a construction perspective, this solution also proved to be suitable for the site conditions, as it is a well-established technology widely used in deep foundations. Conversely, the continuous flight auger pile solution showed better environmental performance in some of the indicators evaluated, with a significant advantage in the mineral resource scarcity category and a slight advantage in other environmental impacts. Therefore, although the continuous flight auger pile solution proved to be more favorable in certain environmental criteria, the precast pile solution was considered the most advantageous alternative overall for the case analyzed, mainly due to its lower cost combined with satisfactory technical and construction performance.