Modelling embankment breaching due to overflow
<p>Correct modelling of embankment breach formation is essential for an accurate assessment of the associated flood risk. Modelling breach formation due to overflow requires a thorough understanding of the geotechnical processes in unsaturated soils as well as erosion processes under supercrit...
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| Formaat: | Thesis |
| Taal: | English |
| Gepubliceerd in: |
2014
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| Onderwerpen: |
| _version_ | 1826264153389531136 |
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| author | van Damme, M |
| author2 | Martin, C |
| author_facet | Martin, C van Damme, M |
| author_sort | van Damme, M |
| collection | OXFORD |
| description | <p>Correct modelling of embankment breach formation is essential for an accurate assessment of the associated flood risk. Modelling breach formation due to overflow requires a thorough understanding of the geotechnical processes in unsaturated soils as well as erosion processes under supercritical flow conditions. This thesis describes 1D slope stability analysis performed for unsaturated soils whose moisture content changes with time. The analysis performed shows that sediment-laden gravity flows play an important role in the erosion behaviour of embankments. The thesis also describes a practical, fast breach model based on a simplified description of the physical processes that can be used in modelling and decision support frameworks for flooding. To predict the breach hydrograph, the rapid model distinguishes between breach formation due to headcut erosion and surface erosion in the case of failure due to overflow. The model also predicts the breach hydrograph in the case of failure due to piping. The assumptions with respect to breach flow modelling are reviewed, and result in a new set of breadth-integrated Navier-Stokes equations, that account for wall shear stresses and a variable breadth geometry. The vertical 2D flow field described by the equations can be used to calculate accurately the stresses on the embankment during the early stages of breach formation. Pressure-correction methods are given for solving the 2D Navier-Stokes equations for a variable breadth, and good agreement is found when validating the flow model against analytical solutions.</p> |
| first_indexed | 2024-03-06T20:03:11Z |
| format | Thesis |
| id | oxford-uuid:2805964c-d5b1-494e-88ff-7a3c6df45b64 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-06T20:03:11Z |
| publishDate | 2014 |
| record_format | dspace |
| spelling | oxford-uuid:2805964c-d5b1-494e-88ff-7a3c6df45b642022-03-26T12:10:20ZModelling embankment breaching due to overflowThesishttp://purl.org/coar/resource_type/c_db06uuid:2805964c-d5b1-494e-88ff-7a3c6df45b64Numerical analysisGeotechnical engineeringApplications and algorithmsProgram development and toolsOrdinary differential equationsDynamics and ocean and coastal engieneeringPartial differential equationsMathematical modeling (engineering)Fluid mechanics (mathematics)Civil engineeringEnglishOxford University Research Archive - Valet2014van Damme, MMartin, CBorthwick, AMorris, M<p>Correct modelling of embankment breach formation is essential for an accurate assessment of the associated flood risk. Modelling breach formation due to overflow requires a thorough understanding of the geotechnical processes in unsaturated soils as well as erosion processes under supercritical flow conditions. This thesis describes 1D slope stability analysis performed for unsaturated soils whose moisture content changes with time. The analysis performed shows that sediment-laden gravity flows play an important role in the erosion behaviour of embankments. The thesis also describes a practical, fast breach model based on a simplified description of the physical processes that can be used in modelling and decision support frameworks for flooding. To predict the breach hydrograph, the rapid model distinguishes between breach formation due to headcut erosion and surface erosion in the case of failure due to overflow. The model also predicts the breach hydrograph in the case of failure due to piping. The assumptions with respect to breach flow modelling are reviewed, and result in a new set of breadth-integrated Navier-Stokes equations, that account for wall shear stresses and a variable breadth geometry. The vertical 2D flow field described by the equations can be used to calculate accurately the stresses on the embankment during the early stages of breach formation. Pressure-correction methods are given for solving the 2D Navier-Stokes equations for a variable breadth, and good agreement is found when validating the flow model against analytical solutions.</p> |
| spellingShingle | Numerical analysis Geotechnical engineering Applications and algorithms Program development and tools Ordinary differential equations Dynamics and ocean and coastal engieneering Partial differential equations Mathematical modeling (engineering) Fluid mechanics (mathematics) Civil engineering van Damme, M Modelling embankment breaching due to overflow |
| title | Modelling embankment breaching due to overflow |
| title_full | Modelling embankment breaching due to overflow |
| title_fullStr | Modelling embankment breaching due to overflow |
| title_full_unstemmed | Modelling embankment breaching due to overflow |
| title_short | Modelling embankment breaching due to overflow |
| title_sort | modelling embankment breaching due to overflow |
| topic | Numerical analysis Geotechnical engineering Applications and algorithms Program development and tools Ordinary differential equations Dynamics and ocean and coastal engieneering Partial differential equations Mathematical modeling (engineering) Fluid mechanics (mathematics) Civil engineering |
| work_keys_str_mv | AT vandammem modellingembankmentbreachingduetooverflow |