Ruptura hidráulica em maciços de barragens de terra x mau funcionamento de vertedores do tipo poço – estudo de caso.

Abstract

Knowledge of the effects of air entrainment in hydraulic structures is a matter that involves many science areas and is of a great relevance to the formulation of design and operational criteria of engineering works. As shaft and morning glory type spillways are concerned, the air entrainment phenomenon is not perfectly known, thus implying in testing their behavior in physical models. In the order hand, the instability of earthen-filled dams as caused by hydraulic disaggregation phenomenon; these due to vibrations and fluctuating pressures induced by existing expansion joints along the crossing structure under hydraulic malfunctioning, needs mathematical modeling since physical modeling of cohesive soils still shows difficulties to the represented. This work presents the verification the instability of earthen dams as caused by malfunctioning of shaft type hydraulic structures, with the support of a mathematical model for analyzing steady flow through saturated porous media. In this study the pressures as resulting from expansion joints and tunnel vibrations, have been evaluated and associated to fluctuating negative and positive pressures inside an earthen dam, subjected to a malfunctioning morning glory type spillways.