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RECENT DEVELOPMENTS IN LABORATORY FROST HEAVE TESTING OF SOILS
Session: Laboratory Testing in Cold Regions / Essais en laboratoire en ingénierie nordique
Mark Nixon, Golder Associates Ltd. (Canada)
J.F. (Derick) Nixon, Nixon Geotech Ltd. (Canada)
This paper describes some recent advances in frost heave testing, suitable for a large scale project where several tests and freeze cycles can be carried out at the same time. Many test procedures freeze the soil too fast for practical field applications (i.e. chilled pipelines). Other shortcomings may include ignoring the side-friction component of stress, blockage of the drainage filter for water intake, inadequate permeability measurements to estimate suction at the freezing front, and only occasional water intake measurements. Each of these oversights involve a non-conservative assessment of the frost heave response of the soil. A test procedure is described that addresses and rectifies each of these issues, and a demonstration series of tests on an artificial soil is carried out. Continuous evaluations of heave, water intake, frost depth, SP, suction and freezing rate are made using software written to accept the raw laboratory data. The results are presented in detail, and illustrate how the frost heave parameters required for design can be extracted from the data. The results are interpreted in terms of the Segregation Potential (SP) method, and also in terms of the Discrete Ice Lens approach.
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