Upheaval buckling resistance of pipelines buried in clayey backfill

This paper presents data from a series of Minidrum Centrifuge tests in which the effects of backfill cover (1 m & 1.3 m) and rock-dump (0.5 m) thickness on the uplift resistance were investigated. All the centrifuge tests were carried out at 30g using natural marine clay. The natural clay samples from offshore were characterised and reconstituted before testing. Field backfill conditions were simulated close to reality in the testing. In each of the tests, the resistance of soil cover, the vertical pipe displacement, and excess pore pressure changes at the pipe invert were measured. The results from this study are compared against the current framework of upheaval buckling behaviour in the literature, and are used to provide a better guideline for the design of offshore pipelines buried in clayey backfills.