Provas de carga estáticas em estacas metálicas tubulares de ponta aberta em um solo tropical

• Autor(a) principal: Nascimento, Breno Breseghelo do
• Data de Publicação: 2019
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tede/12469
• topic: Estacas tubulares metálicas; Estacas de ponta aberta; Prova de carga; Tamponamento; Solos tropicais; Steel pipe piles; Open ended pipe piles; Load tests; Plugging; Tropical soils; ENGENHARIAS::ENGENHARIA CIVIL::GEOTECNICA::MECANICAS DOS SOLOS

Open-ended steel pipe piles are oftenly employed on piled foundations around the world, especially in offshore construction, due to ease of driving, less vibration imposed to the ground and the possibility of using large pile diameters. However, the behavior of this type of pile in tropical soils is not well known, because of lack of studies. Specific phenomenona that occurs on those piles, like plugging, aggravates this scenario. In this study, static load tests were done on steel pipe piles installed in a lateritic soil profile located in the region of Goiânia-GO, aiming at observing their behavior. The piles were installed in an experimental area at EECA-UFG. The area was characterized by means of granulometric analyses, an SPT borehole, and dynamic cone penetrometer PANDA profiles. Five piles installed by jacking were load tested, with varying diameter, installation date, and the tip configuration, open or closed. The soil column height inside the piles and the applied load were measured during jacking. Each pile was load tested in compression with buried lengths of approximately 1,80 m and 3,50 m and, after that, tested in tension. The soil profile at the experimental area was classified as a loose lateritic silty sand, of red color and having low penetration resistance in most of the depth of the profile. All piles were became fully plugged with about 1,00 m of jacked length, continuing that way in the rest of jacking and during load test. The load measured during jacking served as a reasonable prediction for the ultimate load capacity during static load testing and the load x settlement curves for all piles were practically linear until close to failure. Comparing different piles, the closed-ended pile showed less load capacity than the open-ended pile, the higher diameter pile showed greater load capacity than the lesser one and the load capacity of piles of the same dimensions but installed at different dates were different due to changes in soil water content. By applying different load capacity formulas, it was found that the methods have better prediction capacity for longer piles, that the Aoki-Velloso (1975) method have better performance than the Décourt-Quaresma (1978, 1996) method and that the international methods had good and similar performance.