Breach parameters for cascade dams’ breaks using physical, empirical and numerical modeling

Abstract

The environmental, economic, and social consequences of dam breaks are catastrophic and require their prior knowledge to minimize risks. These consequences are directly related to rupture breach parameters, such as formation time and breach geometry (width, height, and lateral slopes). These parameters must be adequately representative of a real rupture to obtain a rupture hydrograph also representative (temporal evolution, volume, and peak flow). This representation becomes more reliable as the closer to the actual consequences of a rupture it is, thus creating conditions for an adequate emergency action plan. This research evaluates the parameters of breach formation for a possible rupture, specifically for the case of reservoirs in a sequence, also called cascade reservoirs. The adopted methodology uses physical reduced models and numerical modeling to define these parameters, trying to represent two cascade dams, based on a reference case, determining their values in each dam after the simulated rupture events.

Methodology to evaluate cascade dams breaks for analysis and safety design

“…According to the results of the application example, peak flow from a cascade dam break evaluated at the Downstream dam was 21% larger and 9 minutes earlier than single dam break analysis values, which agree to the results of physical model's laboratory tests developed by Campos (2020) and Campos et al (2020). The results of the application example refer to a specific pair of dams, highlighting that even if one could be classified as a small dam, it has significant height and volume, and a cascade dam break results can be significantly different from an isolated rupture.…”

“…The detailed physical model's laboratory tests, measurements, and somehow important materials details, which validated results used to develop the proposed equations, can be found at Campos et al (2020).…”

“…The sediment transport evaluation is quite interesting, although this research used synthetic material to represent the dam's materials, as quoted in Campos (2020) and Campos et al (2020).…”