Cantilever Beam Tests on Reinforced Ice

• Main Authors: Ohstrom,Eric G., DenHartog,Stephen L.
• Other Authors: COLD REGIONS RESEARCH AND ENGINEERING LAB HANOVER N H
• Format: Text
• Language: English
• Published: 1976
• Subjects: Snow; Ice and Permafrost; Civil Engineering; *ICE; *SEA ICE; THICKNESS; LOAD DISTRIBUTION; MECHANICAL PROPERTIES; LABORATORY TESTS; CRACKS; TREES; MELTING; ROADS; FAILURE(MECHANICS); REINFORCING MATERIALS; BRIDGES; CANTILEVER BEAMS; WIRE ROPE; DOWELS; *Cold weather construction; Ice roads; Ice bridges; Ice; Ice Sheet; permafrost; Sea ice
• Online Access: http://www.dtic.mil/docs/citations/ADA025380; http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA025380

This report covers a series of cantilever beam tests designed to determined the efficacy of adding reinforcement to an ice cover. Tests were run using 1-in.-diam tree branches, 3/16-in.-diam wire rope and 9/16-in. half-round wood dowels as reinforcement for both seawater and freshwater ice. The results show a definite advantage derived from using reinforcement, even when poorly placed. The results also show that reinforced ice carries a load even after it cracks. Thus, after the initial cracks there is time to remove people and equipment before final breakthrough. One must bear in mind, however, that reinforcement has disadvantages. The darker reinforcement absorbs solar radiation and thereby causes earlier weakening of the ice cover. Also, in many cases the time and effort required to place reinforcement may exceed those required to achieve equal strength by additional thickening of the ice sheet. This study has shown that understanding of the failure mechanism of ice under repetitive loading is poor and that future studies should be performed on this problem. Also, this study covered only cantilever beams. The actual field problem is strengthening a three-dimensional sheet. Hence, distribution and orientation of the reinforcement should be addressed in future studies.