Consulting Engineers and Scientists
Bridge Scour Modelling
Following the recent flooding in Cumbria and the collapse of 26 bridges, Edenvale Young are highlighting our expertiase in the analysis the risk of scour at bridges and consequential collapse. This uses a range of techniques but is based around: assessment of extreme fluvial hydrology; 3D hydro-dynamic modelling of flow through bridge structures; scouring processes; geotechnical instability and risk analysis.
OpenFOAM Results for 1%annual flow probability showing water surface profile at upstream face of bridge at Tavistock
Model Construction Environment for Tavistock Masonry Arch Bridge
Model Construction Environment Showing Surface Model of Tavistock Masonry Arch Bridge
OpenFOAM Mesh Generation Viewed from Downstream of the Tavistock Masonry Arch Bridge
OpenFOAM Results for 1%annual flow probability showing water surface profile at downstream face of bridge at Tavistock
OpenFOAM Results for 1%annual flow probability showing water surface profile and vectors at downstream face of bridge at Tavistock
OpenFOAM Results for 1%annual flow probability showing rendered water surface profile at downstream face of bridge at Tavistock
Assessment of Risk
Assessing the risk of scour and undercutting of foundations and the geotechnical / structural failure of a structure requires careful consideration of a range of factors which affects the response of a bridge in exceptional flow conditions. Edenvale Young can provide the following services including:- |
Site Investigation |
Preparation of appropriate site investigation for use in scour and geotechnical analysis. |
Hydrological Analysis |
Estimation of extreme flood flows using the FEH CD Rom . |
1D-2D (ISIS_TUFLOW) hydraulic modelling to evaluate the regional fluvial conditions including water level. |
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Bridge Modelling |
3D hydrodymanic modelling to evaluate the local flow, velocity, hydro-dynamic forces and pressures. |
Scour and Morphology |
Assessment of morphological change, sediment budgets, clear water scour, live water scour and contraction scour.. |
Geotechnical Analysis |
Assessment of abutment and pier stability due to sliding, bearing, stability and other modes of failures. |
Fluvial and Geotechnical Instrumentation |
Advice on the installation of water level and scour montoring and warning systems. |
Risk Assessment |
Evaluation of Risk in accordance with CIRIA 125 Control of Risks |
Protection |
Advice and design of bridge pier protection. |
3-D Hydraulic Modelling
Typical masonry arched bridge Click on the radar buttons above to view input and output from OpenFOAM / Inter Flow for a 1% annual probabailty flood event for this bridge at Tavistock in Devon. |
OpenFOAM / Interflow
Three-Dimensional modelling with OpenFOAM / Inter Flow has a number of significant advantages in terms of evaluating scour and the response of a bridge structures in extreme fluvial events. This incudes improved understanding of flow veloities and bed shear stresses adjacent to a pier, abutment or caisson.
In addition, OpenFOAM / Inter Flow allows the user to interrogate the model to determine the hydrodymanic loading on the bridge elevation and in extreme conditions uplift force / bursting forces on the bridge deck. This can used within the geotechnical / structural analysis to determine the factor of safety against collapse for an existing bridge or provide design parameters for a new struture. |
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Bridge Geometry including the configuration of cut waters, bridge piers, arches, foundations and abutments influence flow velocities around and through the structure and are critical to the process of scouring for individual bridges. The use of OpenFOAM. OpenFOAM modelling allows the configuration of the structure to be adjusted rapidly. |
Technology & Skills
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Validation / Verification
The use of Open Foam / Open Flow has been evaluated at the Universtiy of Bath as part of a research programme associated with scour, breach development and geotechnical failure of flood defence embankments. In addition, this work has also included physical model testing of piers and caissons subject to wave loading in shallow water conditions (Read More). -
Animations
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Critical Infrastructure
Failure mechanism associated with hydraulic loading, scour at bridges and other hydraulic structures is complex and the use of simple traditional methods may not reflect the value of the asset or give sufficient information to permit decisions to be made on the future of the asset (Read More).
Channel Migration
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River Severn - Buttington
Bank erosion and channel migration associated with changes to the hydraulic regime of a river can threaten existing structures including bridges and flood embankments. In time this may result in the loss of critcal infrastructure. The Meandras software package can be used as a suite of techniques includign historical review to assess the probable migration of a river.