Stability of artificial subaqueous slopes in sandy soils under wave loads
Shallow foundation structures in marine environments can rarely be placed on top of the sea floor. Weak soils usually need to be excavated to place the structure on more stable ground. Steep but stable slopes of the resulting pit meet both economic and ecologic aims as they minimise material movemen...
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fttuhamburg:oai:tore.tuhh.de:11420/7250 2023-08-20T04:02:44+02:00 Stability of artificial subaqueous slopes in sandy soils under wave loads Bubel, Julian Pick, Marc-André Grabe, Jürgen 2015-05 http://hdl.handle.net/11420/7250 en eng International Conference on Offshore Mechanics and Arctic Engineering - OMAE 2015 978-079185647-5 Stabilität von künstlichen Unterwasserböschungen in sandigen Böden International Conference on Offshore Mechanics and Arctic Engineering, OMAE: (2015-05) http://hdl.handle.net/11420/7250 2-s2.0-84947801610 Conference Paper Other 2015 fttuhamburg 2023-07-28T09:21:55Z Shallow foundation structures in marine environments can rarely be placed on top of the sea floor. Weak soils usually need to be excavated to place the structure on more stable ground. Steep but stable slopes of the resulting pit meet both economic and ecologic aims as they minimise material movement and sediment disturbance. This paper focuses changes of geometry of submarine slopes in non-cohesive soils (erosion, sedimentation, breach failure, liquefaction failure) due to surface waves. After Terzaghi the angle between slope and the horizontal of the ground surface of cohesionless soil is at most equal to the critical state friction angle, as obviously true for dry soil. However, it can be observed that natural submarine slopes of sandy soils are always mildly sloped. During the construction of artificial submarine pits under offshore conditions it should be considered that the long-term slope-inclination is less than onshore due to hydrodynamic actions (e. g. flow, waves, earthquakes). Large surface waves cause excess pore water pressures within the soil body, leading to a reduction of effective stresses and in case of submarine slopes to changes of the slope geometry depending on wave length L, wave height H, water depth h and soil properties (permeability k, relative density Dr). During our preliminary work we investigated such processes based on the coupling of linear wave theory and linear quasistatic consolidation theory (e.g. [1]). With the help of numerical modelling we solved corresponding equations considering also materially nonlinear consolidation. However, deformations were always limited by used Lagrangian-FEM. Recent developments at our Institute enable the use of an Eulerian-FEM approach with an u-p-Formulation for fully saturated soil [2]. This allows larger deformations of the subaqueous slope to be numerically investigated. Conference Object Arctic TUHH Open Research (TORE - Technische Universität Hamburg) |
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Open Polar |
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TUHH Open Research (TORE - Technische Universität Hamburg) |
op_collection_id |
fttuhamburg |
language |
English |
description |
Shallow foundation structures in marine environments can rarely be placed on top of the sea floor. Weak soils usually need to be excavated to place the structure on more stable ground. Steep but stable slopes of the resulting pit meet both economic and ecologic aims as they minimise material movement and sediment disturbance. This paper focuses changes of geometry of submarine slopes in non-cohesive soils (erosion, sedimentation, breach failure, liquefaction failure) due to surface waves. After Terzaghi the angle between slope and the horizontal of the ground surface of cohesionless soil is at most equal to the critical state friction angle, as obviously true for dry soil. However, it can be observed that natural submarine slopes of sandy soils are always mildly sloped. During the construction of artificial submarine pits under offshore conditions it should be considered that the long-term slope-inclination is less than onshore due to hydrodynamic actions (e. g. flow, waves, earthquakes). Large surface waves cause excess pore water pressures within the soil body, leading to a reduction of effective stresses and in case of submarine slopes to changes of the slope geometry depending on wave length L, wave height H, water depth h and soil properties (permeability k, relative density Dr). During our preliminary work we investigated such processes based on the coupling of linear wave theory and linear quasistatic consolidation theory (e.g. [1]). With the help of numerical modelling we solved corresponding equations considering also materially nonlinear consolidation. However, deformations were always limited by used Lagrangian-FEM. Recent developments at our Institute enable the use of an Eulerian-FEM approach with an u-p-Formulation for fully saturated soil [2]. This allows larger deformations of the subaqueous slope to be numerically investigated. |
format |
Conference Object |
author |
Bubel, Julian Pick, Marc-André Grabe, Jürgen |
spellingShingle |
Bubel, Julian Pick, Marc-André Grabe, Jürgen Stability of artificial subaqueous slopes in sandy soils under wave loads |
author_facet |
Bubel, Julian Pick, Marc-André Grabe, Jürgen |
author_sort |
Bubel, Julian |
title |
Stability of artificial subaqueous slopes in sandy soils under wave loads |
title_short |
Stability of artificial subaqueous slopes in sandy soils under wave loads |
title_full |
Stability of artificial subaqueous slopes in sandy soils under wave loads |
title_fullStr |
Stability of artificial subaqueous slopes in sandy soils under wave loads |
title_full_unstemmed |
Stability of artificial subaqueous slopes in sandy soils under wave loads |
title_sort |
stability of artificial subaqueous slopes in sandy soils under wave loads |
publishDate |
2015 |
url |
http://hdl.handle.net/11420/7250 |
genre |
Arctic |
genre_facet |
Arctic |
op_relation |
International Conference on Offshore Mechanics and Arctic Engineering - OMAE 2015 978-079185647-5 Stabilität von künstlichen Unterwasserböschungen in sandigen Böden International Conference on Offshore Mechanics and Arctic Engineering, OMAE: (2015-05) http://hdl.handle.net/11420/7250 2-s2.0-84947801610 |
_version_ |
1774713331791167488 |