Numerical Modeling of Test Embankment Supported by Stone Column Foundation
Luciano Souza Junior1; Mario Riccio1; Silvana Macêdo de Vasconcelos2; Marcio Almeida3
1 Universidade Federal de Juiz de Fora; 2 COPPE/ Universidade Federal do Rio de Janeiro; 3 COPPE/Universidade Federal de Juiz de Fora
doi:10.20906/CPS/CILAMCE2017-0034
Resumo
Embankments on soft soils are a sensitive engineering issue. Over the time, many alternatives have been developed to mitigate the problematic behavior of those structures. Almeida (2010) presents a series of New Techniques available to soft soil foundation treatment. Among these techniques, the use of stone columns is a frequent strategy that promotes the dissipation of pore pressure due to its natural draining characteristic, reducing the expected settlement and also the time for its stabilization. This present study has as aim, analyze numerically, using the finite element software PLAXIS 2D, v.8.2, the performance of a test embankment with 4,60 m thickness that sits above an 8,6m thick soil layer. This structure was constructed to validate project criteria that increased the usual column spacing. Thus, the primary goal of this earthwork is to provide insights around the behavior of a small part to extrapolate it to the bigger picture. In this way, it is possible to observe the development of settlements and general stability to prove whether the proposed parameters are valid. Nevertheless, it is impossible to state anything about the factor of safety and other factors as pore pressure, stresses and displacements in different parts of the soil body. Hence, a numerical modeling is needed. Usually, the finite element analyses of vertical drains consider an axisymmetric unit cell that comprises the area of influence of a single column. In this experiment, a different approach was considered. Using a simplified plane-strain model based on a geometrical transformation that reduces the original column width (Tan et al. 2008), the model was developed considering the proposed geometry and typical soil parameters from shore of Rio de Janeiro city. Furthermore, this method was proposed having as a primary principle the correspondence of the column drainage in axisymmetric and plane-strain settings. Which leads to smaller plane-strain columns diameters and larger flow paths dimensions based on the conversion of vertical d
Palavras-chave: Stone columns foundation; 3D for 2D transformation; Safety factor against failure