Spillway rock scour experience and analysis - the Australian scene over the past four decades

Bollaert, E.; Lesleighter, EJ

doi:10.14264/uql.2014.35

Cited by 7 publications

(4 citation statements)

References 5 publications

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“…Block response regarding high-velocity jet impact P Bollaert (2011) [102] 3D scour assessment downstream of the penstocks P Bollaert (2012) [56] Evaluation of the rock erosion at the plunge pool walls P Bollaert et al ( 2013) [57] Quasi-3D numerical predictions P Pan et al (2013) [103] Estimation of final scour depth S and R Huang et al (2013) [104] Modifications of the EIM soft bedrock erosion P Bollaert and Lesleighter (2014) [60] Spillway rock scour S George (2015) [83] Influence of a 3D geological structure on the erosion of blocks P Tanaka and Sato (2015) [105] Relationship between damage and hydraulic parameters -Pells et al (2015) [15] Assessment of the erosion for unlined spillways case S Pells (2016) [1] Spillways erosion evaluation S…”

Section: Summary and Discussionmentioning

confidence: 99%

“…The plunging jet pathway relies upon air drag and ballistics. The falling jet module can determine the jet pathway length L from issuance to the impact point, the longitudinal distance of the plunging jet from issuance to the impact point, the jet velocity (V j ), and the jet diameter (D j ) at the impact point (Equations ( 9) and ( 10)) [60,61]. The falling jet module (Figure 8) clarifies how the geometrical and hydraulic parameters of the plunging jets are changed from outlet exit to impact point of plunge pool surface.…”

Section: Semi-analytical Methodsmentioning

confidence: 99%

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A Review on Existing Methods to Assess Hydraulic Erodibility Downstream of Dam Spillways

Kashtiban

Saeidi

Farinas

et al. 2021

Water

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In recent years, rock scouring or erosion downstream of dams has become an increasing dam safety concern. Several theoretical, semi-theoretical, semi-analytical and numerical methods can be used to assess the rock erosion in hydraulic structures. Semi-theoretical approaches determine the correlation between the erosive intensity of fluid flow and the resistive capacity of rock. Such approaches establish the scour thresholds as a function of erosive intensity of water and several rock mass indices by using in situ data and a curve-fitting approach. In some studies, the excavatability index, initially developed for rock mass stability analysis, was used to analyse the rock mass resistance in hydraulic erodibility analysis. The effectivity and weight of the geomechanical parameters used are yet to be determined on the basis of the erodibility phenomenon. The semi-analytical methods are developed on the basis of the mechanical and hydraulic interaction of rock mass and water. Four methods developed by Bollaert et al. are important in determining the erodibility in the plunge pool, but they are not applicable in the case of spillways. They used the comprehensive fracture mechanics for closed-end joints, quasi-steady impulsion, and dynamic impulsion (DI) for blocky rock erosion. The application of these methods to each site is necessary to identify constants that are difficult to determine. Few numerical methods are available to assess the rock mass erosion in hydraulic structures. In the case of numerical methods, the erosive agent is indistinct, and the hydraulic hazard parameter on the spillway surface is almost challenging to apply. This study comprehensively reviews the mechanism of erosion and the methods for assessing the risk of potential rock mass erosion downstream of dams and hydraulic structures. The advantages and disadvantages of all methods are discussed and the potential future research directions in this domain are proposed.

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Section: Summary and Discussionmentioning

confidence: 99%

Section: Semi-analytical Methodsmentioning

confidence: 99%

A Review on Existing Methods to Assess Hydraulic Erodibility Downstream of Dam Spillways

Kashtiban

Saeidi

Farinas

et al. 2021

Water

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“…Bedrock scour downstream of a dam is a complex physical process and the complete understanding of the air-water-rock phase interaction in the scouring process is required. The free-falling jet could be split into three different modules, namely the falling jet module, plunge pool module and rock mass module as defined by Bollaert and Lesleighter (2014) in Figure 1.…”

Section: Rock Scourmentioning

confidence: 99%

Physical model study of bedrock scour downstream of dams due to spillway plunging jets

Bosman¹,

Basson²

2020

J. S. Afr. Inst. Civ. Eng.

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The erosive power of a free-falling high-velocity water jet, flowing from a dam spillway, could create a scour hole downstream of the dam, endangering the foundation of the dam. Despite extensive research since the 1950s, there is presently no universally agreed method to predict accurately the equilibrium scour depth caused by plunging jets at dams. These formulae yield a large range of equilibrium scour dimensions. The hydrodynamics of plunging jets and the subsequent scour of a rectangular, horizontal and vertical fissured rock bed were investigated in this study by means of a physical model. Equilibrium scour hole geometries for different fissured dimensions (simulated with rectangular concrete blocks tightly prepacked in a regular rectangular matrix), for a range of flow rates, plunge pool depths, and dam height scenarios were experimentally established with 31 model tests. From the results, non-dimensional formulae for the scour hole geometry were developed using multi-linear regression analysis. The scour depth results from this study were compared to various analytical methods found in literature. The equilibrium scour hole depth established in this study best agrees with that predicted by the Critical Pressure method.

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“…This is done before releasing it into a channel downstream. The design of stilling basins and energy dissipators has been addressed in several studies [2][3][4][5][6]. The development of cutting-edge technologies and materials, computer software, and the expansion of the number of features of measuring devices are the basis for the continuation of studies on the design of stilling basins and energy dissipators.…”

Section: Introductionmentioning

confidence: 99%

Effect of Various Kinds of Stilling Basin’s Baffle Blocks Arrangement on River Bed Scour

Abdelkader

2022

IJESNR

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The management of water retaining structures and their environmental impacts are critical aspects of hydraulic engineering studies. From an environmental perspective, hydraulic structure planning is primarily concerned with the design of the water-releasing sections (outlet) of the water retaining structures. It is essential that such structures are properly designed in order to meet the requirements of sustainability of the surrounding ecological system. This study aims to examine the impact of hydraulic jump stilling basin length and energy dissipation blocks on scour depth and reach an optimum performance of the stilling basin. To this end, an experimental study was conducted to investigate the effect of the stilling basin's baffle blocks on the river bed scour downstream of a water-retaining structure. Several hydraulic parameters were incorporated in the analysis and design of the stilling basin. The study introduces a novel approach to estimating the maximum scour based on a non-linear regression model.

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Spillway rock scour experience and analysis - the Australian scene over the past four decades

Cited by 7 publications

References 5 publications

A Review on Existing Methods to Assess Hydraulic Erodibility Downstream of Dam Spillways

A Review on Existing Methods to Assess Hydraulic Erodibility Downstream of Dam Spillways

Physical model study of bedrock scour downstream of dams due to spillway plunging jets

Effect of Various Kinds of Stilling Basin’s Baffle Blocks Arrangement on River Bed Scour

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