(INFORMATION RETRIEVAL ABSTRACT) 'SETTLEMENT OF A PIPELINE ON THAWING PERMAFROST'

KEY WORDS ice; ice lenses; permafrost; pipelines; settlement; soil mechanics ABSTRACT A buried oil pipeline in permafrost will thaw the frozen soil around it, and will settle as the thawed soil consolidates. Because the amount of ice in the soil varies from point to point along the pipe alignment, the settlement will be uneven, and will induce bending in the pipe. Thaw settlement estimates from single boreholes give no information about the possible magnitude of differential settlements, and instead statistical measures of the 'intensity of fluctuations in thaw settlement have to be used. Alternative sources of the required data are suggested, and two different ways of estimating the effects on the pipe are described, one way being based on random process theory and the other on statistical simulation. The flexural stiffness of the pipe modifies the settlement, and methods of taking this effect into account are explained