A Computational Model for the Analysis of Uplift Pressures and Fluid Flow in the Jucazinho RCC Dam

Resumo

The Jucazinho dam is of the Roller Compacted Concrete (RCC) type, completed in 1998. The first flood
was in 2004 with a 1,4m thick spill, causing deterioration of part of the dissipation basin. This situation triggered
investigation services to assess the structural integrity of the structure. It was found that the drainage gallery
presented several pathological manifestations arising from the water seepage through the concrete monolith. In
2017, there were maintenance and consolidation services throughout the dam structure, paying particular attention
to cracks and the rehabilitation of the dam gallery. Several studies were carried out on the dam: (i) verification of
the quality of the materials used throughout the structure; (ii) exceptional seismicity actions that could cause major
problems preventing its use; (iii) global stability analysis. But the effects of seepage flow in the concrete were not
deeply analyzed. These considerations justify the occurrence of existing manifestations and serve as a reference
for monitoring the dam's safety. In order to analyze the water seepage that occurs in Jucazinho dam, the 2D Finite
Element Method (FEM) was used using the ABAQUS software, considering: (i) flow through porous media with
coupled fluid diffusion and stress analysis; (ii) finite elements with combined displacement and pressure degrees
of freedom; (iii) the solver of non-symmetric equations; (iv) steady-state analysis. Following these considerations,
this article presents a brief review of the literature on the subject and the knowledge of the physical parameters of
the dam. Subsequently, it introduces the physical and mathematical formulations that characterize the problem to
be studied in Jucazinho dam. With the numerical simulations the following results were achieved: (i) the
equipotential and flow lines inside the monolith; (ii) the displacements and stresses for the fully coupled analysis.
These parameters are important for future investigations and safety monitoring of the Jucazinho dam. Reference
simulations performed without fluid flow in the confined medium demonstrate that the values obtained differ
completely from the simulations that considered the water seepage inside the concrete, reaffirming the importance
of considering flow analysis coupled with stress analysis.