Particle image velocimetry analysis of the protective layer in embankment dams

The growing requirement imposed by dam safety regulations and guidelines necessitates the improvement and rehabilitation of rockfill embankment dams. These hydraulic structures are of great importance, and they can be subjected to overtopping flows which can significantly compromise the structural i...

Full description

Saved in:
Bibliographic Details
Main Authors: Nisal Deelaka Halaba Arachchige Senarathna, Théo Dezert, Fjóla Guðrún Sigtryggsdóttir
Format: Article
Language:English
Published: Frontiers Media S.A. 2025-01-01
Series:Frontiers in Built Environment
Subjects:
Online Access:https://www.frontiersin.org/articles/10.3389/fbuil.2024.1502168/full
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1841555073901002752
author Nisal Deelaka Halaba Arachchige Senarathna
Théo Dezert
Théo Dezert
Fjóla Guðrún Sigtryggsdóttir
author_facet Nisal Deelaka Halaba Arachchige Senarathna
Théo Dezert
Théo Dezert
Fjóla Guðrún Sigtryggsdóttir
author_sort Nisal Deelaka Halaba Arachchige Senarathna
collection DOAJ
description The growing requirement imposed by dam safety regulations and guidelines necessitates the improvement and rehabilitation of rockfill embankment dams. These hydraulic structures are of great importance, and they can be subjected to overtopping flows which can significantly compromise the structural integrity. One of the defense mechanisms utilized is the placement of riprap on the downstream shoulder of the dam. This article explores eight experimental tests comprising of four different dam model configurations and investigates the possibility of Particle Image Velocimetry (PIV) techniques to explore the characteristics of the protective riprap layer, such as breach initiation, failure mechanism, and velocity pattern. The models varied from full to half dam profiles, constituted of placed or dumped riprap, with or without downstream toe support, and with or without downstream shell material. Leveraging the PIV technique, the study provides insight into the area of breach initiation within riprap protection on the downstream shoulder of rockfill embankment dams and thus breach initiation of protected rockfill dams. The study brings to light that for models with placed riprap, the initiation occurs simultaneously at the top and the bottom of the protective layer confirming the assertions made in prior studies regarding a failure mechanism marked by a sliding process. The study further confirms that for structures with toe support, the breach initiation occurs at the top of the protective layer. This analysis also revealed that in the case of dumped riprap, the precise position of the breach initiation was indeterminate. Furthermore, the analysis revealed that there is a significant drop in the velocity readings at the downstream section of the riprap layer when supported by a toe, underscoring the significance of having toe support. Another revelation from this analysis was the contrasting velocity readings with substantially higher readings for placed riprap as compared to dumped riprap reaffirming the fact that placed riprap can endure higher discharges as compared to dumped riprap. Furthermore, this investigation also detected that a graph of the velocity pattern depicting the placed riprap exhibited a higher singular peak while such a graph depicting the dumped riprap exhibited a bimodal characteristic.
format Article
id doaj-art-396b97c834b74796a2c52559e7608ed7
institution Kabale University
issn 2297-3362
language English
publishDate 2025-01-01
publisher Frontiers Media S.A.
record_format Article
series Frontiers in Built Environment
spelling doaj-art-396b97c834b74796a2c52559e7608ed72025-01-08T06:12:08ZengFrontiers Media S.A.Frontiers in Built Environment2297-33622025-01-011010.3389/fbuil.2024.15021681502168Particle image velocimetry analysis of the protective layer in embankment damsNisal Deelaka Halaba Arachchige Senarathna0Théo Dezert1Théo Dezert2Fjóla Guðrún Sigtryggsdóttir3Department of Civil and Environmental Engineering, Norwegian University of Science and Technology (NTNU), Trondheim, NorwayDepartment of Civil and Environmental Engineering, Norwegian University of Science and Technology (NTNU), Trondheim, NorwayFI-NDT, Gustave-Eiffel University, Bouguenais, FranceDepartment of Civil and Environmental Engineering, Norwegian University of Science and Technology (NTNU), Trondheim, NorwayThe growing requirement imposed by dam safety regulations and guidelines necessitates the improvement and rehabilitation of rockfill embankment dams. These hydraulic structures are of great importance, and they can be subjected to overtopping flows which can significantly compromise the structural integrity. One of the defense mechanisms utilized is the placement of riprap on the downstream shoulder of the dam. This article explores eight experimental tests comprising of four different dam model configurations and investigates the possibility of Particle Image Velocimetry (PIV) techniques to explore the characteristics of the protective riprap layer, such as breach initiation, failure mechanism, and velocity pattern. The models varied from full to half dam profiles, constituted of placed or dumped riprap, with or without downstream toe support, and with or without downstream shell material. Leveraging the PIV technique, the study provides insight into the area of breach initiation within riprap protection on the downstream shoulder of rockfill embankment dams and thus breach initiation of protected rockfill dams. The study brings to light that for models with placed riprap, the initiation occurs simultaneously at the top and the bottom of the protective layer confirming the assertions made in prior studies regarding a failure mechanism marked by a sliding process. The study further confirms that for structures with toe support, the breach initiation occurs at the top of the protective layer. This analysis also revealed that in the case of dumped riprap, the precise position of the breach initiation was indeterminate. Furthermore, the analysis revealed that there is a significant drop in the velocity readings at the downstream section of the riprap layer when supported by a toe, underscoring the significance of having toe support. Another revelation from this analysis was the contrasting velocity readings with substantially higher readings for placed riprap as compared to dumped riprap reaffirming the fact that placed riprap can endure higher discharges as compared to dumped riprap. Furthermore, this investigation also detected that a graph of the velocity pattern depicting the placed riprap exhibited a higher singular peak while such a graph depicting the dumped riprap exhibited a bimodal characteristic.https://www.frontiersin.org/articles/10.3389/fbuil.2024.1502168/fulldam safetyrockfill damdam breachPIVriprap
spellingShingle Nisal Deelaka Halaba Arachchige Senarathna
Théo Dezert
Théo Dezert
Fjóla Guðrún Sigtryggsdóttir
Particle image velocimetry analysis of the protective layer in embankment dams
Frontiers in Built Environment
dam safety
rockfill dam
dam breach
PIV
riprap
title Particle image velocimetry analysis of the protective layer in embankment dams
title_full Particle image velocimetry analysis of the protective layer in embankment dams
title_fullStr Particle image velocimetry analysis of the protective layer in embankment dams
title_full_unstemmed Particle image velocimetry analysis of the protective layer in embankment dams
title_short Particle image velocimetry analysis of the protective layer in embankment dams
title_sort particle image velocimetry analysis of the protective layer in embankment dams
topic dam safety
rockfill dam
dam breach
PIV
riprap
url https://www.frontiersin.org/articles/10.3389/fbuil.2024.1502168/full
work_keys_str_mv AT nisaldeelakahalabaarachchigesenarathna particleimagevelocimetryanalysisoftheprotectivelayerinembankmentdams
AT theodezert particleimagevelocimetryanalysisoftheprotectivelayerinembankmentdams
AT theodezert particleimagevelocimetryanalysisoftheprotectivelayerinembankmentdams
AT fjolaguðrunsigtryggsdottir particleimagevelocimetryanalysisoftheprotectivelayerinembankmentdams