Sedimentation engineering

Cover
Half Title
Title Page
Copyright Page
Editorial Board
Contributors
Table of Contents
Foreword
Acknowledgements
List of main symbols
List of main definitions
1 Introduction
	1.1 General
	1.2 Scope of this manual
	1.3 Reading guide
2 Design process
	2.1 Introduction
	2.2 Boundary conditions
		2.2.1 Introduction
		2.2.2 Hydraulic conditions
		2.2.3 Morphological conditions
		2.2.4 Geotechnical conditions
	2.3 Risk assessment
		2.3.1 Introduction
		2.3.2 Fault tree analysis
		2.3.3 Safety factor
		2.3.4 Failure probability approach
	2.4 Protective measures
		2.4.1 Introduction
		2.4.2 Bed protection
		2.4.3 Falling apron
		2.4.4 Other counter measures
	2.5 Examples
		2.5.1 Introduction
		2.5.2 Determination of the length of a bed protection with a reliability index
		2.5.3 Determination of the failure probability using a FORM approach
		2.5.4 Determination scour depth using a safety factor
3 Design tools
	3.1 Introduction
	3.2 Mathematical scour and erosion models
		3.2.1 Introduction
		3.2.2 Types of modelling
		3.2.3 Large-scale RANS models
			3.2.3.1 Shallow water modelling
			3.2.3.2 Turbulence modelling
		3.2.4 High-resolution hydrodynamic models
			3.2.4.1 Hydrodynamic model LES
			3.2.4.2 Application of LES
			3.2.4.3 Hydrodynamic model DNS
		3.2.5 Particle-based multiphase models
			3.2.5.1 Soil mechanics: MPM
			3.2.5.2 Hydraulic model: SPH
	3.3 General scour
		3.3.1 Introduction
		3.3.2 Overall degradation or aggradation
		3.3.3 Constriction scour
		3.3.4 Bend scour
		3.3.5 Confluence scour
	3.4 Local scour
		3.4.1 Introduction
		3.4.2 Time-dependent scour
		3.4.3 Equilibrium scour
		3.4.4 Conditions of transport
	3.5 Geotechnical aspects
		3.5.1 Introduction
		3.5.2 Liquefaction
		3.5.3 Effects of groundwater flow
		3.5.4 Non-homogeneous subsoils
		3.5.5 Upstream and side slopes
		3.5.6 Failure length
	3.6 Examples
		3.6.1 Introduction
		3.6.2 Constriction scour
		3.6.3 Critical slope angles and failure lengths
4 Initiation of motion
	4.1 Introduction
	4.2 Flow and turbulence characteristics
		4.2.1 Introduction
		4.2.2 Sills
		4.2.3 Bridge piers and abutments
		4.2.4 Indicative values of flow velocity and turbulence
	4.3 Non-cohesive sediments
		4.3.1 Introduction
		4.3.2 Shields diagram
		4.3.3 Design approaches
		4.3.4 Critical flow velocity
		4.3.5 Rock
	4.4 Cohesive Sediments
		4.4.1 Introduction
		4.4.2 Critical shear stress
		4.4.3 Critical flow velocity
		4.4.4 Empirical shear stress formulas
		4.4.5 Erosion rate
		4.4.6 Peat
	4.5 Examples
		4.5.1 Introduction
		4.5.2 Turbulence at bridge piers and groynes
			4.5.2.1 Bridge Piers
			4.5.2.2 Groynes
		4.5.3 Critical flow velocity of peat
		4.5.4 Critical mean flow velocity and critical bed shear stress in an open channel with sand dunes
		4.5.5 Critical depth-averaged flow velocity according to Mirtskhoulava (1988)
		4.5.6 Comparison critical strength of clay
5 Jets
	5.1 Introduction
	5.2 Flow characteristics
		5.2.1 Introduction
		5.2.2 Flow velocities
		5.2.3 Hydraulic jump
	5.3 Time scale of jet scour
	5.4 Plunging jets
		5.4.1 Introduction
		5.4.2 Calculation methods
		5.4.3 Discussion
	5.5 Two-dimensional culverts
		5.5.1 Introduction
		5.5.2 Calculation methods
		5.5.3 Discussion
	5.6 Three-dimensional culverts
		5.6.1 Introduction
		5.6.2 Calculation methods
		5.6.3 Discussion
	5.7 Ship-induced flow and erosion
		5.7.1 Introduction
		5.7.2 Scour due to the return current of a sailing vessel
		5.7.3 Scour due to propeller and thruster jets
		5.7.4 Discussion
	5.8 Scour at broken pipelines
	5.9 Scour control
	5.10 Examples
		5.10.1 Introduction
		5.10.2 Two-dimensional scour downstream a broad-crested sill
		5.10.3 Three-dimensional scour downstream a short-crested overflow weir
		5.10.4 Two-dimensional scour downstream an under flow gate
6 Sills
	6.1 Introduction
	6.2 Flow characteristics
	6.3 Scour depth modelling in the Netherlands
		6.3.1 Introduction
		6.3.2 Scour depth formula
		6.3.3 Characteristic time
		6.3.4 Relative turbulence intensity
		6.3.5 Scour coefficient
		6.3.6 Non-steady flow
		6.3.7 Upstream supply of sediment
	6.4 Upstream scour slopes
		6.4.1 Introduction
		6.4.2 Hydraulic and morphological stability criterion
		6.4.3 Undermining
	6.5 Additional measures
	6.6 Field experiments
		6.6.1 Introduction
		6.6.2 Hydraulic and geotechnical conditions
		6.6.3 Discussion
			6.6.3.1 Upstream scour slope
			6.6.3.2 Undermining
			6.6.3.3 Time scale
			6.6.3.4 Equilibrium scour depth
			6.6.3.5 Evaluation brouwers dam experiments
		6.6.4 Experiences Eastern Scheldt
	6.7 Example
		6.7.1 Introduction
		6.7.2 Critical upstream scour slope downstream a sill
7 Abutments and groynes
	7.1 Introduction
	7.2 Geometry characteristics and flow patterns
		7.2.1 Introduction
		7.2.2 Wing-wall abutments
		7.2.3 Spill-through abutments
		7.2.4 Vertical-wall abutments
		7.2.5 Flow pattern
	7.3 Dutch modelling
		7.3.1 Introduction
		7.3.2 Breusers approach
		7.3.3 Closure procedures
	7.4 Equilibrium scour depth
		7.4.1 Introduction
		7.4.2 Calculation methods
		7.4.3 Discussion
	7.5 Combined scour
		7.5.1 Introduction
		7.5.2 Combined local scour and constriction or bend scour
	7.6 Failure mechanism and measures to prevent local scour
		7.6.1 Introduction
		7.6.2 Scour slopes
		7.6.3 Outflanking
		7.6.4 Riprap protection
	7.7 Examples
		7.7.1 Introduction
		7.7.2 Scour due to lowering of existing abutments
		7.7.3 Influence of the permeability of an abutment on the scour
8 Bridges
	8.1 Introduction
	8.2 Characteristic flow pattern
		8.2.1 Introduction
		8.2.2 Submerged bridges
	8.3 Time scale
	8.4 Equilibrium scour depth
		8.4.1 Introduction
		8.4.2 Calculation methods
		8.4.3 Pressure scour
		8.4.4 Discussion
	8.5 Effects of specific parameters
		8.5.1 Introduction
		8.5.2 Pier shape
		8.5.3 Alignment of the pier to the flow
		8.5.4 Gradation of bed material
		8.5.5 Group of piers
	8.6 Scour slopes
		8.6.1 Introduction
		8.6.2 Single cylindrical pier
		8.6.3 Other types of piers
		8.6.4 Winnowing
	8.7 Measures to prevent local scour
		8.7.1 Introduction
		8.7.2 Riprap protection
		8.7.3 Mattress protection
		8.7.4 Deflectors
	8.8 Example
		8.8.1 Introduction
		8.8.2 Local scour around bridge piers
			8.8.2.1 Slender piers
			8.8.2.2 Wide piers
9 Case studies on prototype scale
	9.1 Introduction
	9.2 Camden motorway bypass bridge pier scour assessment (RHDHV)
		9.2.1 Introduction
		9.2.2 Assessment of scour
		9.2.3 Scour assessment results
		9.2.4 Constriction scour
		9.2.5 Abutment scour
		9.2.6 Pier scour
		9.2.7 Numerical Model Verification
		9.2.8 Scour mitigation
		9.2.9 Conclusions
	9.3 Project Waterdunen (Svasek)
		9.3.1 Introduction
		9.3.2 Bed protection
		9.3.3 Hydraulic loads
		9.3.4 Scour depth
		9.3.5 Additional remarks
			9.3.5.1 Gate control
			9.3.5.2 Safety factors
			9.3.5.3 Sensitivity calculations
			9.3.5.4 Turbulence
	9.4 Full-scale erosion test propeller jet (Deme)
		9.4.1 Introduction
		9.4.2 Objective of the full-scale erosion tests and estimated flow field
		9.4.3 Scour prediction methods
		9.4.4 Results
	9.5 Scour due to ship thrusters in the Rotterdam port area (Port of Rotterdam)
		9.5.1 Introduction
		9.5.2 Full-scale test with inland vessels at the Parkkade
			9.5.2.1 Scope
			9.5.2.2 Observed scour depth versus predictions with Breusers formulas
			9.5.2.3 Observed versus predicted scour for thrusters with PIANC formulas
			9.5.2.4 Conclusions
		9.5.3 Scour due to operational use of Maasvlakte quay wall for large seagoing container vessels
			9.5.3.1 Observed scour
			9.5.3.2 Computed scour
			9.5.3.3 Conclusions
	9.6 Crossing of high voltage power line (Witteveen & Bos)
		9.6.1 Introduction
		9.6.2 Scour for a single pier
		9.6.3 Scour for multiple piers
		9.6.4 Results and discussion
	9.7 Scour development in front of culvert (van Oord)
		9.7.1 Introduction
		9.7.2 Initial bottom protection and scouring
		9.7.3 New design bottom protection
		9.7.4 Result redesign
	9.8 Bed protection at railway bridge in a bypass of the river Waal (Deltares)
		9.8.1 Introduction
		9.8.2 Flow condition
		9.8.3 Scouring
		9.8.4 Designed bed protection
		9.8.5 Final remarks
	9.9 Pressure scour around bridge piers (Arcadis)
		9.9.1 Introduction
		9.9.2 Flow conditions
		9.9.3 Scour computation
		9.9.4 Results
	9.10 Bed protection at the weir at Grave in the river Meuse (Rijkswaterstaat)
		9.10.1 Introduction
		9.10.2 Scope
		9.10.3 Flow condition
		9.10.4 Scour and bed protection
		9.10.5 Condition after the flood
		9.10.6 Hindcast
References