Experimental methods for local-scale characterization of hydro-morphodynamic dam breach processes. Breach detection, 3D reconstruction, flow kinematics and spatial surface velocimetry

Abstract

A set of tests on failure by overtopping of earth dams was performed under hydraulic and geotechnical controlled conditions in a medium-scale facility located at the Portuguese National Laboratory for Civil Engineering. The flow over the breaching dam is three-dimensional and exhibits several length scales. Instrumentation must be able to capture this complexity and scale amplitude and must be non-intrusive. This work presents a summary of the instrumentation layout as well as its main components and measuring methods that were used and/or developed to address these issues. The emphasis is placed on post-processing analysis of digital imagery, for which there is detailed exposition of the adopted methods and an evaluation of its suitability for its intended purpose.