Estimation of Settlements in Shallow Foundations Based on the Theory of Linear Viscoelasticity

Juliane Cristina Gonçalves

Federal University of Juiz de Fora, Brazil

Abstract: In this work, the main focus is a methodology for the analysis of the settlements of a spread footing underneath the center of compression load area applying the Theory of Linear Viscoelasticity. A review of the foundations of Linear Viscoelasticity and the development leading to the equation for solving the problem are briefly presented. It was possible to represent the viscoelasticity behavior of materials through rheological models formed by a combination of springs, dashpots and friction blocks. Their creep functions may be adopted to model in approximate value the behavior of materials or structural elements and foundations. The rheological model in this study consists of a spring in series with a Kelvin model (a spring and a dashpot in parallel). The method is illustrated with an example as following: footing of width 1.2 m and average applied stress 174.2 kN/m². Settlement growth is observed over time. The estimated values are always very small, reaching only 6.4 mm. It is already expected such a low value due to footing width, average applied stress, coefficient of viscosity, transverse elastic modulus, Poisson's ratio and soil elastic modulus. Settlements tend toward stabilizing after about 300 days.

Key words: estimation of settlements, shallow foundation, footing foundation, linear viscoelasticity