Laboratory Test of Scour Under Ice: Data and Preliminary Results
An ice cover may be a major factor determining how alluvial channel morphology evolves in rivers, and a significant influence on bridge pier scour. This was confirmed with real-time monitoring of the bed elevation and extensive bathymetry measurements made in the Mississippi River, the Missouri Rive...
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ftdtic:ADA422726 2023-05-15T16:37:24+02:00 Laboratory Test of Scour Under Ice: Data and Preliminary Results Hains, Decker Zabilansky, Leonard ENGINEER RESEARCH AND DEVELOPMENT CENTER HANOVER NH COLD REGIONS RESEARCH AND ENGINEERING LAB 2004-04 text/html http://www.dtic.mil/docs/citations/ADA422726 http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA422726 en eng http://www.dtic.mil/docs/citations/ADA422726 APPROVED FOR PUBLIC RELEASE DTIC AND NTIS Physical and Dynamic Oceanography Snow Ice and Permafrost *SEDIMENT TRANSPORT *ICE VELOCITY LABORATORY TESTS MONITORING REAL TIME MORPHOLOGY POLYSTYRENE SURFACE ROUGHNESS ICE FORMATION ALLUVIUM BATHYMETRY FLOW RATE SURFACE PROPERTIES HYDROSTATICS PIERS MEAN RIVERS EQUATIONS BANKS(WATERWAYS) MISSISSIPPI RIVER CHANNELS(WATERWAYS) BRIDGES MISSOURI RIVER OPEN WATER *SCOUR BRIDGE SCOUR HYDRAULIC INSTRUMENTATION Text 2004 ftdtic 2016-02-21T07:54:46Z An ice cover may be a major factor determining how alluvial channel morphology evolves in rivers, and a significant influence on bridge pier scour. This was confirmed with real-time monitoring of the bed elevation and extensive bathymetry measurements made in the Mississippi River, the Missouri River, and the White River in Vermont. In all cases, the sediment process was significantly different from what existing sediment equations would predict. This laboratory study examined the sensitivity of various parameters affecting sediment transport under ice. Twenty tests were conducted in CRREL's refrigerated flume using mean flow velocities in the clear-water scour range. Three surface conditions were modeled: open water, a floating cover, and a fixed cover, simulating ice frozen to the river banks and a bridge pier, with a superimposed hydrostatic head that could be created by an upstream ice jam. The ice cover was simulated using Styrofoam with both smooth and rough surfaces. Under clear-water scour, the equilibrium scour depths for the fixed and floating covers were similar, but up to 21% higher than those found for open water. The cover roughness altered the velocity distribution and caused live-bed scour even when the mean flow velocity was 0.86 times the critical velocity for bed movement. When the average velocity was 0.93 times critical velocity, the pressure flow caused live-bed scour. A combination of increased cover roughness and pressure flow resulted in the largest equilibrium scour depth. Text Ice permafrost Defense Technical Information Center: DTIC Technical Reports database |
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Open Polar |
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Defense Technical Information Center: DTIC Technical Reports database |
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ftdtic |
language |
English |
topic |
Physical and Dynamic Oceanography Snow Ice and Permafrost *SEDIMENT TRANSPORT *ICE VELOCITY LABORATORY TESTS MONITORING REAL TIME MORPHOLOGY POLYSTYRENE SURFACE ROUGHNESS ICE FORMATION ALLUVIUM BATHYMETRY FLOW RATE SURFACE PROPERTIES HYDROSTATICS PIERS MEAN RIVERS EQUATIONS BANKS(WATERWAYS) MISSISSIPPI RIVER CHANNELS(WATERWAYS) BRIDGES MISSOURI RIVER OPEN WATER *SCOUR BRIDGE SCOUR HYDRAULIC INSTRUMENTATION |
spellingShingle |
Physical and Dynamic Oceanography Snow Ice and Permafrost *SEDIMENT TRANSPORT *ICE VELOCITY LABORATORY TESTS MONITORING REAL TIME MORPHOLOGY POLYSTYRENE SURFACE ROUGHNESS ICE FORMATION ALLUVIUM BATHYMETRY FLOW RATE SURFACE PROPERTIES HYDROSTATICS PIERS MEAN RIVERS EQUATIONS BANKS(WATERWAYS) MISSISSIPPI RIVER CHANNELS(WATERWAYS) BRIDGES MISSOURI RIVER OPEN WATER *SCOUR BRIDGE SCOUR HYDRAULIC INSTRUMENTATION Hains, Decker Zabilansky, Leonard Laboratory Test of Scour Under Ice: Data and Preliminary Results |
topic_facet |
Physical and Dynamic Oceanography Snow Ice and Permafrost *SEDIMENT TRANSPORT *ICE VELOCITY LABORATORY TESTS MONITORING REAL TIME MORPHOLOGY POLYSTYRENE SURFACE ROUGHNESS ICE FORMATION ALLUVIUM BATHYMETRY FLOW RATE SURFACE PROPERTIES HYDROSTATICS PIERS MEAN RIVERS EQUATIONS BANKS(WATERWAYS) MISSISSIPPI RIVER CHANNELS(WATERWAYS) BRIDGES MISSOURI RIVER OPEN WATER *SCOUR BRIDGE SCOUR HYDRAULIC INSTRUMENTATION |
description |
An ice cover may be a major factor determining how alluvial channel morphology evolves in rivers, and a significant influence on bridge pier scour. This was confirmed with real-time monitoring of the bed elevation and extensive bathymetry measurements made in the Mississippi River, the Missouri River, and the White River in Vermont. In all cases, the sediment process was significantly different from what existing sediment equations would predict. This laboratory study examined the sensitivity of various parameters affecting sediment transport under ice. Twenty tests were conducted in CRREL's refrigerated flume using mean flow velocities in the clear-water scour range. Three surface conditions were modeled: open water, a floating cover, and a fixed cover, simulating ice frozen to the river banks and a bridge pier, with a superimposed hydrostatic head that could be created by an upstream ice jam. The ice cover was simulated using Styrofoam with both smooth and rough surfaces. Under clear-water scour, the equilibrium scour depths for the fixed and floating covers were similar, but up to 21% higher than those found for open water. The cover roughness altered the velocity distribution and caused live-bed scour even when the mean flow velocity was 0.86 times the critical velocity for bed movement. When the average velocity was 0.93 times critical velocity, the pressure flow caused live-bed scour. A combination of increased cover roughness and pressure flow resulted in the largest equilibrium scour depth. |
author2 |
ENGINEER RESEARCH AND DEVELOPMENT CENTER HANOVER NH COLD REGIONS RESEARCH AND ENGINEERING LAB |
format |
Text |
author |
Hains, Decker Zabilansky, Leonard |
author_facet |
Hains, Decker Zabilansky, Leonard |
author_sort |
Hains, Decker |
title |
Laboratory Test of Scour Under Ice: Data and Preliminary Results |
title_short |
Laboratory Test of Scour Under Ice: Data and Preliminary Results |
title_full |
Laboratory Test of Scour Under Ice: Data and Preliminary Results |
title_fullStr |
Laboratory Test of Scour Under Ice: Data and Preliminary Results |
title_full_unstemmed |
Laboratory Test of Scour Under Ice: Data and Preliminary Results |
title_sort |
laboratory test of scour under ice: data and preliminary results |
publishDate |
2004 |
url |
http://www.dtic.mil/docs/citations/ADA422726 http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA422726 |
genre |
Ice permafrost |
genre_facet |
Ice permafrost |
op_source |
DTIC AND NTIS |
op_relation |
http://www.dtic.mil/docs/citations/ADA422726 |
op_rights |
APPROVED FOR PUBLIC RELEASE |
_version_ |
1766027690820763648 |