Experimental device and numerical support in order to study mudflows: its laws of evolution, runout distances and velocity field

Abstract

If the dam break problem is a long standing studied subject, since the classical works of Ritter, Dressler and Stoker, along with many others in the theoretical and experimental point of view, mainly through commercial softwares well-stablished from the literature (Dambreak models), there will be found, on the other hand, a small number of works about eventual tailings dam breaks and even a smaller number of them that treat, in a critical sense, the hydrodynamic aspects of the enormous volumes released from this type of accident tied to the flowing fluid's rheology. Based on this motivation, this doctorate research has as a general objective to determine the hydrographs produced by the "gradual" and "instantaneous" opening gate (dam-break type) and its influence on the evolution of the velocity of fronts (and runout distances) of viscoplastic materials (kaolinitic clay and Carbopol gels), as well as measure the velocity profile over the flow's depth. Structured on three (3) parts that complete themselves, the project provides experimental tests which will be done in a laboratory (controlled situation), using automated devices and precision equipments (sonic transducers, laser, high resolution digital cameras, etc). The various experimental settings will be fully monitored in plan and profile view, over an inclined plane and channel, which should total about 280 tests. Finally, it's worth pointing out that the expected impact of the project is at the complete understanding of the hydrodynamic process of dam break phenomena (with repercussion in the risks management area) and in the implementation of a velocity profile measurement system along depth the viscoplastic fluid flow, by means of the image velocimetry technique (STIV) in laboratory channels, which gives originality and novelty. (AU)