Centrifuge tests for evaluation of submarine-mudflow hydroplaning and turbidity currents

Abstract

Physical modelling studies of submarine landslides in a 5° slope were conducted to assess the occurrence of hydroplaning and turbidity currents. The centrifuge modelling did not aim to simulate the complete mudflow mechanism, but rather focused on assessing the hydroplaning and the turbidity current conditions. Four tests were performed using kaolin clay in a drum centrifuge (N = 40). The initial water content of the slurry and the pressure associated with the release of the mixture inside the centrifuge were varied during the tests in order to simulate different flow rates. The test results were evaluated by means of pore pressure and total stress measurements at the mudflow−slope interface in order to identify the flow conditions in which hydroplaning takes place. Froude and Reynolds numbers were also used to identify the turbidity current and hydroplaning phenomena. The particle image velocimetry technique was used to obtain the velocity field in order to complement the analysis.