Frost Heave Induced Pipe Strain of an Experimental Chilled Gas Pipeline

摘要

A full-scale chilled gas pipeline experiment was conducted in Fairbanks, Alaska to develop the design criteria for pipeline construction in arctic regions. The test pipeline had a length of 105 m and a diameter of 0.9 m. One-third of the pipeline was located in permafrost and the remaining was in non-permafrost. The monitoring data were collected from December 1999 to January 2005 including both freezing and thawing phases. In the transition zone between frozen and unfrozen soil, the foundation material experienced a vertical movement caused by differential frost heave. The test results indicated that the bending action was the main factor for the circumferential and longitudinal strain distribution in the pipeline. The circumferential strain ranged from about 100 to 500 με during freezing. The maximum tensile and maximum compressive strains along the pipeline were approximately located at the edges of the transition zone.