In the past, a significant amount of investigation into the development of critical buckling strain limit state criteria for pipelines has been conducted and a number of critical strain criteria have been proposed. However, the availability of comparative experimental data that have been collected under representative pipeline operating conditions has been somewhat limited.

Over the past eight years, more than 50 full-scale pipeline tests under representative field conditions have been conducted at the University of Alberta (U of A) in Edmonton, Alberta, Canada. Experimental parameters have included the diameter-to-thickness (D/t) ratio, the internal pressure to yield pressure ratio (p/py), and the presence or absence of a circumferential girth-weld at the mid-height of the specimen. Critical strain values were determined for the majority of these test specimens and were then compiled in an attempt to assess current limit state design criteria for governing critical buckling strains.

This paper summarizes the critical buckling strain values from a total of 38 tests that have been conducted at U of A at the present time. The experimental results are then used to assess a number of previously developed critical strain criteria.

This content is only available via PDF.