Experimental Study on Soil-Pipeline Interaction Using EPS Backfill

Underground lifelines, such as gas and water pipelines, can be affected by the movement of the adjacent ground. Earthquake-induced Permanent Ground Deformation (PGD), occurring as surface fault deformation, liquefaction-induced soil movements, and landslides, can severely affect such buried pipelines. To design pipelines against earthquakes, the pipelines should have enough stiffness and strength against a force conveyed from the adjacent ground. For the pipelines constructed in areas where such PGD is expected, the pipe stiffness should be increased with a larger diameter, thickness or strength, or the soil-pipe interaction should be reduced. In this paper, the effect of EPS (Expanded Poly-Styrene) for backfill on the reduction of soil-pipeline interaction was evaluated as an earthquake-resistant design.