The performance of most geotechnical structures is highly governed by environmental factors, particularly in tropical regions where there are very pronounced dry and wet seasons. Design of earth retaining structures generally tend to be too conservative due to the uncertainty generated by the incorporation of environmental variables.
Those variables control the soil unsaturated response and in addition to the known insufficiency of the basic models used in traditional designs they are responsible for conservative designs. Rainfall is the main aspect that affects the soil properties of a particular site.
It modifies the soil suction potential, according to the degree of saturation caused by the soil-atmosphere interaction. Currently, state-of-the-art numerical tools allow to simulate the influence of those variables in the behaviour of earth retaining structures.
This paper analyses the possible implications of the use of numerical simulations for the design, which include, in the mathematical formulation, the suction as a main parameter. The hypoplastic model for unsaturated response was used.
Numerical simulations performed with the use of traditional and modern constitutive models obtained encouraging results that reveal the importance of include suction in design processes.