Centrifuge modelling of a buried pipeline below an embankment

Abstract

This paper presents the results of physical modelling tests carried out on a geotechnical centrifuge to investigate the influence of an embankment load on the behaviour of a pipeline buried in clayey soil. A series of centrifuge tests was performed on a pipeline model buried in a kaolin–sand soil mixture to model the behaviour of a pipeline crossing below an embankment. The embankment was modelled using unsaturated sand layers built above the kaolin–sand soil. The test set-up allowed the acquisition of both deformations corresponding to the longitudinal bending, and forces developed on the pipe during the consolidation of the soil due to the application of the embankment layers. The influence of pipe embedment was also investigated through tests with different soil heights above the pipe crest. The results indicated that the force transmitted to the pipeline comprises two components: a force due to the self-weight of the soil above the pipe and a force developed owing to soil settlement during the consolidation phase. The force component due to the self-weight of the soil decreased with depth, whereas the force component due to consolidation remained nearly constant. Test results were compared with results obtained from different analytical approaches documented in the literature to understand the behaviour of buried pipelines under similar loading conditions.