Development of the original ice borehole jack

• Published in: Canadian Journal of Civil Engineering
• Main Authors: Masterson, D. M., Graham, W.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1996
• Subjects: General Environmental Science; Civil and Structural Engineering; Arctic; Ice Sheet
• Online Access: http://dx.doi.org/10.1139/l96-019; http://www.nrcresearchpress.com/doi/pdf/10.1139/l96-019

A tool to obtain the engineering strength and stiffness properties of ice in situ is described; these properties are needed by engineers to estimate ice forces on structures and ice load bearing capacity. The strength and stiffness of the ice sheet will vary with depth and thus it is necessary to have a measure of strength that includes variation with depth to provide a means of determining average or global strength properties. To determine these properties it was necessary to have a tool that would measure strength and stiffness at 0.3–0.5 m intervals through the ice cover. A hydraulically activated borehole jack, operating at a pressure of 70 MPa and capable of fitting in a 150 mm diameter hole, was developed. This lightweight device has proven capable of measuring strength and stiffness properties and has been used by engineers and researchers in several parts of the arctic. It is now accepted as a standard tool for the verification of floating airstrips and other similar structures. Key words: ice, ice testing, ice testing in situ, ice strength, borehole testing, in situ borehole tests, engineering strength, ice compressive strength.