DEEP BENCH MARKS IN CLAY AND PERMAFROST AREAS

• Main Authors: Bozozuk,M., Johnston,G. H., Hamilton,J. J.
• Other Authors: NATIONAL RESEARCH COUNCIL OF CANADA OTTAWA (ONTARIO) DIV OF BUILDING RESEARCH
• Format: Text
• Language: English
• Published: 1963
• Subjects: CLAY; CANADA; PERMAFROST; DRILLING MACHINES; JACKS(LIFTS); ANCHORS(STRUCTURAL); Canada; The Bench; permafrost
• Online Access: http://www.dtic.mil/docs/citations/AD0436204; http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=AD0436204

This paper describes the design and use of deep bench marks by the Division of Building Research Council of Canada. The bench marks consist of an inner pipe protected by an outer casing from the effects of seasonal ground movements and frost action. In sensitive clays the bench mark is installed by jacking or driving the outer casing with relatively simple equipment. In stiffer clays it is inserted in an augered hole and then turned and pushed to refusal with a drill rig. In permafrost areas, the bench mark is placed in a drilled or steamed hole to a depth at which the lower portion of the inner rod is securely anchored in the perennially frozen ground. Details of bench mark assemblies and installation techniques for soft clays, stiff clays, and frozen ground are described. (Author) Available from National Research Council of Canada, Div. of Building Research, at $.25.