Abstract: Stress changes induced by tunnel excavation and static pipe bursting inevitably lead to soil movements, and cause adverse effects on existing pipelines. Although the pipe-soil interaction has attracted increasing research attention worldwide, a simplified design code has not been developed to directly estimate bending strains of existing pipelines due to tunnel excavation and static pipe bursting. In this study, we use the commercial software of ABAQUS to systemically simulate the tunnel-soil-pipeline and pipe bursting-soil-pipeline interactions, and develop a single dimensionless plot for calculating bending strains of existing pipelines due to static pipe bursting and tunneling by using equivalent soil-pipe stiffness. Results of field monitoring and centrifuge tests are adopted to verify the proposed dimensionless plot. The ratio of the maximum pipeline curvature to the maximum ground curvature correlates well with the proposed equivalent subgrade soil stiffness. By given the ground displacement profile, pipe dimension, pipe material properties, and soil properties, engineers can apply the proposed dimensionless plot to directly estimate maximum pipeline curvature and/or strains due to tunneling and pipe bursting.

Key words: differential ground movements, underground pipelines, bending deformation, calculation chart