Pressures of Thermal Origin Exerted by Ice Sheets upon Hydraulic Structures (Les Poussees d'Origine Thermique Exercees par les Couverts de Glace sur les Structures Hydrauliques)

• Main Authors: Drouin,M., Michel,B.
• Other Authors: COLD REGIONS RESEARCH AND ENGINEERING LAB HANOVER N H
• Format: Text
• Language: English
• Published: 1974
• Subjects: Snow; Ice and Permafrost; Civil Engineering; Thermodynamics; *ICE; *THERMAL EXPANSION; *RESERVOIRS; *DAMS; STRESSES; HEAT TRANSFER; DENSITY; THICKNESS; MECHANICAL PROPERTIES; STABILITY; CRACKS; CANADA; ATMOSPHERIC TEMPERATURE; BIBLIOGRAPHIES; ELASTIC PROPERTIES; RATES; STRAIN(MECHANICS); CRYSTALS; TERRAIN; STRENGTH(MECHANICS); PRESSURE; RHEOLOGY; TRANSLATIONS; RIVERS; SOLAR RADIATION; LAKES; THRUST; CRYSTALLOGRAPHY; Ice sheets; Ice crystals; Hydraulic structures; Ice ramparts; Canada; Ice; Ice Sheet; permafrost
• Online Access: http://www.dtic.mil/docs/citations/ADA014938; http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA014938

Ice expands or contracts as a function of temperature variation. Thus, partial or total restriction of the expansion of a sheet of ice gives rise to conditions of stress which the engineer must consider in analyzing the stability of hydraulic structures subjected to them. Each site at which a hydraulic structure is installed has its own particular characteristics; the principal ones are the following: meteorological conditions, texture and structure of the ice, topography of banks, thickness of the ice, thickness and density of the snow covering the ice, and cracks in the ice sheet. The objective of this research was to study pressures of thermal origin exerted by ice sheets as a function of these parameters. Variations in air temperature are also the cause of the formation of ice ramparts and pressure crests. Ramparts are formed at the peripheries of lakes whose shores offer little resistance to the free expansion of ice sheets. At present, Canadian engineers are using values from 15,000 to 30,000 kg per linear meter (10,000 to 20,000 lbs per linear foot) in their calculations. A thrust equal to 22,500 kg per linear meter (15,000 lbs per linear foot) has the same capability of overturning a concrete gravity dam 12.5 meters (38 feet) high as the thrust exerted by the water. An Additional volume of concrete, on the order of 30 percent, is necessary to assure the stability of such a structure subjected to this thrust exerted by the ice. These values indeed point up the importance of more precisely determining the intensity of this force as a function of the numerous variables found in nature. Trans. of Laval Univ., Quebec. Mechanics of Ice Lab. Rept. no. S-23.