Numerical simulation of flooding process of a collapsible soil with raft foundation

Resumo

Collapsible soils are those that suffer a considerable reduction in volume when exposed to an increase in water content, even without the addition of external loading. Numerical and experimental simulation of this phenomenon to understand the behavior of shallow and deep foundations is relatively complex, since it involves phenomena related to unsaturated soils and transient flow. In view of this, the present study aims to present the numerical simulation of the flooding process of a collapsible soil in the Federal District of Brazil (Geotechnical Experimental Field of the University of Brasilia), where was built a physical reference model consisting of a raft
and a system of vertical drains. The simulation was carried out using the Finite Element Method in the Plaxis software, with the implementation of the Costa and Cavalcante hydraulic model, proposed in 2021. After comparing the results of the numerical analysis with those obtained in the field, it was observed that the model used managed to properly reproduce the flooding process carried out, in such a way that it can also be used to simulate numerically, together with an adequate mechanical model, the phenomenon of collapse and the behavior of more complex foundation systems in such a situation.