Verificação do requisito de deformações aceitáveis no projeto de estacas: caso prático

Abstract

This study aims to evaluate the need for settlement analysis in the design of deep foundations on piles when sizing is based on geotechnical bearing capacity with the adoption of a conventional safety factor. For this purpose, a methodology was developed and applied to a case study involving four real construction projects executed in Fortaleza, Ceará, using root piles. The bearing capacity of the piles was estimated through semi-empirical methods based on the SPT N-value, adopting a safety factor equal to 2. Settlements were estimated experimentally and by the methods proposed by Poulos and Davis and by Aoki and Lopes, for comparative purposes. The methodology was subsequently reapplied considering a reduction of the safety factor to 1.5, aiming to assess the sensitivity of settlements to variations in this parameter. The results indicated that, for the analyzed projects, the estimated settlements presented low magnitudes and good agreement with the experimental values, even with the reduction of the safety factor. For piles installed in the soil profiles of the studied sites, the exclusive adoption of bearing capacity with a conventional safety factor tends to result in acceptable settlements. However, the combined verification of bearing capacity, settlements, and load tests should not be neglected in the design of deep foundations.