Estudo de problemas de percolação e drenagem em estruturas hidráulicas utilizando modelos eletroanalógicos dos tipos R e RC.

Abstract

In this work, electroanalytical models of types R and RC were implanted to study flow problems in earth dams, channels and wells, in which the analogy is made through the correspondences between the parameters of flow and storage of electricity in the resistors and capacitors of the model and the flow and storage of water in the porous media. In the earth-dam models, the effective length of a horizontal filter for homogeneous isotropic and anisotropic dams, based on an impermeable foundation, was studied. Adequate ranges for filter lengths for the isotropic and anisotropic cases were suggested, with lower percolation criteria through the dam body and higher minimum thickness values ​​of the saturated zone, in order to increase the stability of the structure. For the uncoated channels the water losses by percolation for a trapezoidal channel in homogeneous isotropic soil on a horizontal impermeable layer with several conditions for the depth of the impermeable layer and the water table. The results obtained were compared with those of Dupuit-Forchheimer and Ernst, with a satisfactory agreement with respect to Ernst's theory and divergent with respect to Dupuit-Forchheimer's theory, for which reasons were clarified. Validity bands of the results of the model with the theory were established, with respect to dimensionless parameters of the channels. The problem of the impermeable formations in aquifers was studied for regular impermeable barriers by varying the position with respect to the center where the pumping occurs, with perpendicular barriers to the radial direction and a case with a barrier aligned in the radial direction, observing the effects in the well production. For nonradial barriers, the influence of the position on the well flow is relatively large while the radial in the considered position has practically no influence on productivity. Models of real field structures in the State of Paraíba were also implemented and tested to emphasize the usefulness of the model in the solution of practical problems. Suggestions were made for the continuation of future researches in order to solve more complex problems with different contours.