Modelagem centrífuga de fluxos de detritos submarinos

Abstract

This work presents a study of submarine debris flows in a gentle slope (5 degrees angle). The simulations were performed in a geotechnical drum centrifuge (N = 40) with the objective of determining the velocity profile for underwater debris flows with the occurrence of the aquaplaning phenomenon. Several changes were implemented in the existing COPPE drum centrifuge. The use of practically all of its perimeter, the use of a rugged ramp, instrumented curve and adequately sealed ramp, and collection of images and instrumentation in 4 positions of the model. In the simulations of underwater debris flows the moisture content of the mixture was varied by measuring the viscosity and yield stress values for each mixture. Another variable studied was the released pressure of the mixtures inside the centrifuge. Results of total stress and porepressure over time and of video images were obtained. The particle image velocimetry technique was used to obtain velocity profiles. All these results allowed to indicate the tests with occurrence of aquaplaning. In these cases an intrusion of a thin layer of water was observed between the slipped mud and the slope bed also observed with the measured velocity profile.