Análise técnica e financeira da presença da água no dimensionamento de um muro de flexão

Abstract

This study analyzes the technical and financial impact of water presence on the design of cantilever reinforced concrete retaining walls, without the use of drainage systems. The research was conducted through comparative analyses of three distinct water conditions: absence of water, partial presence (2.5 m), and high presence (5.0 m from the base of the wall). The methodology involved calculating the acting loads, performing stability checks in accordance with NBR 11682:2009, and fully designing the structural reinforcement. In addition, direct costs related to the consumption of concrete and steel were estimated, without considering any drainage solutions, in order to isolate the effects of water on structural performance. The results showed that rising water table levels lead to significant increases in acting forces, especially in overturning moments, making this the most critical failure mode. It was also observed that the required amount of reinforcement increased more sharply than the concrete volume, resulting in a global cost increase of over 40% under the high water condition. The study concludes that the absence of drainage systems in areas with elevated water tables directly affects both the structural safety and financial feasibility of retaining walls, highlighting the importance of thoroughly evaluating hydrogeotechnical conditions during the early stages of design.