466 4TH CAN. PERMAFROST CONF. (1982) In situ frost heave testing using cold plates

• Main Authors: J. F. Nixon, J. R. Ellwood, W. A. Slusarchuk
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Sion; Yukon; permafrost
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.534.4806; http://pubs.aina.ucalgary.ca/cpc/CPC4-466.pdf

The concept is introduced of a circular cold plate as a device for determining the frost heave char-acteristics or susceptibility of soils in situ. The advantages include (i) the ability to test the in situ, undisturbed soil and groundwater conditions, not subjected to possible sampling disturbance, and (ii) the ability to test a much larger volume of soil than is possible in standard laboratory tests. A parallel might be drawn with the use of the plate bearing test in conjunction with standard laboratory compres-sion tests in determining the stress-strain characteristics of soils in conventional geotechnical practice. The design, fabrication, installation, and instrumentation of several 0.76 m diameter cold plates are described. Instrumentation includes heave measurement rods, thermistors, and earth pressure cells. These plates have been successfully installed and operated in the south Yukon and Calgary. Results from these tests provide a bridging between small-scale laboratory testing and eventual frost heave design for large diameter, buried, chilled gas pipelines. Results from one of two cold plate installations at the pipeline research facility in Calgary are pre-sented in detail, and brief comparisons are made with the behaviour of full-size pipeline test sections. The in situ cold plate test provides valuable test data within a few months that are a valuable aid to long-term frost heave predictions.