Estacas carregadas lateralmente: avaliação de um método empírico para a previsão de esforços internos

• Autor(a) principal: Santos, Isabella Christine de Paula
• Data de Publicação: 2016
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tede/9985
• topic: Estacas carregadas lateralmente; Previsão de esforços internos; Método empírico; Método dos elementos finitos; Método das diferenças finitas; Laterally loaded piles; Prediction internal efforts; Empirical method; Finite element method; Finite differences method; ENGENHARIA CIVIL::GEOTECNICA

Several constructions are subject of large lateral forces, for example, “off-shore” structures; retaining structures foundations of high buildings and bridges; ports and towers transmission lines. Thus, the general objective of this work is to evaluate an empirical method for predicting internal efforts in laterally loaded piles, which is based on Standard Penetration Test (SPT), making the use of this method simpler. To conduct this study, it was used the numerical tools DIANA, based on the Finite Element Method (FEM), and Excel spreadsheet, in which the Finite Differences Method (FDM) and the Empirical Method studied to obtain internal efforts at the piles (bending moment, displacement and stress) were implemented. Several cases of isolated piles subject only to horizontal load or bending moment were evaluated, by varying parameters such as the relative length and diameter of the pile; and soil properties, simulating soils with different deformabilities. Three analyzes were performed to the studied problem, considering an elastic-linear model: parametric analyzes, comparisons between "continuous medium" and "horizontal reaction coefficient" and evaluation of the empirical method. Also, it was searched to get a relation for the maximum horizontal stress from the penetration resistance index (NSPT). It was observed that both, the displacement and the bending moment, depend quite on the soil properties, and that soil stresses do not vary much in the pile projection. The soil upper layers are the ones which suffer greater loading influence applied to the surface. As the soil deformability increases, the internal efforts of piles diminish. There is a critical length for the piles. It was checked that relations from Broms (1964) e de Pyke e Beiake (1985) for the horizontal reaction coefficient of soil, which best represent the behavior of piles subjected to laterally loading. The empirical method evaluated could well represent the cases studied in relation to the bending moments generated. It has been suggested that the truss length (L0) most appropriate for the piles in certain types of soils, and this depends on the type of soil and the geometric characteristics of the pile. Relations were obtained for a K coefficient of proportionality, which relates the necessary variables to estimate the maximum horizontal stress, which is dependent on soil type and geometrical characteristics of the pile.