Avaliação da Capacidade de Carga Geotécnica e Recalque de Estacas Hélice Contínua Monitorada em um Edifício de Rio Branco – AC

Abstract

The geotechnical load capacity and displacement of Continuous Flight Auger (CFA) piles were evaluated in this thesis. The piles examined were installed during construction work for the building of the Superintendência Regional de Polícia Federal (DPF/AC) in Rio Branco, Acre. The building consists of three distinct blocs divided by dilation joints; each block consisting of a basement, four upper floors, an engine house and a heliport. The building is found on deep foundations (continuous flight auger piles), as well as on shallow foundations (single footings). The latter was not analyzed, as shallow foundations are out of scope of this thesis. The geotechnical load capacity of the CFA piles was evaluated based on soil stratigraphy and Nsrr obtained from SPT logs. A computational program developed in Excel was used to compare various load capacity methods presented by Aoki & Velloso (1975), Décourt & Quaresma (1978/1996), Antunes & Cabral (1996), Monteiro (1997), Gotlieb et al. (2000) and Kárez & Rocha (2000). The displacement of the pile top was estimated using the program Cálculo do Recalque de Estacas (Módulo 15), which is based on Aoki & Lopes’s (1975) method, and accounts for both soil displacement and pile elastic deformation. Results from these various methods were used to calculate pile length, which was then compared to as-built pile condition. A wide range of load capacity values was found using the various methods examined here. As a consequence, the calculated pile lengths varied accordingly, but all shorter than the as-built piles. The estimated pile displacement values varied from 1 mm to 8 mm. The angular distortion (β) between contiguous piles did not interfere in the functionality of the building.