Author(s): S. Cordero; A. Cagninei; D. Poggi

Linked Author(s): Silvia CORDERO, Davide Poggi

Keywords: Dam-break flow; Physical model; Image-analysis technique; Three-dimensional flow; Laboratory experiments

Abstract: The propagation of dam-break waves along a hillslope is studied by means of a physical model and an image-analysis technique. The facility and the calibration phase are described. Preliminary results are given. Floods due to the breaching of earthen dams are a potential hazard to downstream areas. The failure of a small dam can affect a limited area; nevertheless, a lack in emergency plans may result in considerable damage to people life and properties. This requires analysis of potential impacts which imply the ability to predict the potential flooded area and the wave magnitude. The key factor is the estimate of flow depths and flow velocity. The majority of the small dams considered have no natural inflow and no valley downstream, so the propagation of the wave due to a dam-break cannot be studied as a one-dimensional (1D) or a two-dimensional (2D) depth-averaged flow. Diffusion along the direction perpendicular to the breach axis plays a key role in the assessment of the potential flooded area. The downstream slope and roughness plus the collapse dynamic are the main factors to be considered when assessing the wave front width. Fraccarollo and Toro were among the first to record punctual measures of a 3D dam-break flow. Cochard and Ancey and, more recently, Aureli et al. and Elkholy et al. obtained the water depth field using three different imaging techniques. The goal here is to measure the development of a 3D dam-break flow (i.e., water depth and wave front velocity) on a laboratory physical model. The technique is an image-analysis procedure based on light absorption. The experimental set-up, the light calibration, and preliminary results are shown.

DOI: https://doi.org/10.3850/978-981-11-2731-1_314-cd

Year: 2018