Physical modelling of soil-pipe interaction for buried pipelines subjected to cyclic surface loading and internal pressurization
Physical modelling of soil-pipe interaction for buried pipelines subjected to cyclic surface loading and internal pressurization
Pipelines, by transporting liquid and gas, play a vital role as critical lifelines in modern infrastructure. Typically, these pipelines buried underground experience substantial stresses resulting from external cyclic loading such as traffic and soil movements, and internal pressures from conveyed fluids, including their variations over time, that have a significant influence on the structural response and long-term performance of buried pipelines. A small-scale laboratory model has been developed to study the soil-pipe interaction under these combined conditions. The experimental set-up consists of a rigid tank filled with sand, containing aluminium pipes (100 mm diameter, 2 mm wall thickness) scaled to one-third of real steel pipelines. Internal pressurization of the water-filled pipe is achieved using a Controlled Pressure Volume device, allowing the internal pressure to reach 2 MPa during testing. Surface loading with up to 1000 cycles is applied using a vertical actuator acting on a rigid plate. The instrumentation includes strain gauges on the pipe and settlement sensors on the pipe and plate. The test campaign evaluates how internal pressure influences pipe deformation and surrounding soil stress distribution under cyclic surface loading. The small-scale results obtained for both pressurized and non-pressurized cases are compared to provide a better understanding of the system behaviour. This comparison helps identify potential sources of conservatism in current design practice and highlights the importance of accounting for internal pressurization and soilpipe interaction.
Keywords: Physical modelling; Soil structure interaction; Buried gas pipelines; Internal pressure
Ali Ajami; Christophe Dano; Orianne Jenck; Fabrice Emeriault; A. Mertz; M. Polo; Mohammed Nait Ali; Gerard Nespoulous
11th International Conference on Physical Modelling in Geotechnics (ICPMG2026)
Session 3: Resilient geotechnical infrastructure
https://doi.org/10.53243/ICPMG2026-72