Pipeline Response to Ground Deformations Induced by Tunneling

This paper introduces a simplified analytical methodology for estimating bending moments and axial loads on buried pipelines due to ground movements caused by tunneling in soft soil. The method combines Winkler models for describing the pipe-soil interaction, with closed-form analytical solutions that use cavity shape-mode parameters for estimating the tunnel-induced free-field ground deformations. Analytical approximations for the vertical and horizontal Winkler spring stiffness coefficients are interpreted from three-dimensional numerical analyses. The proposed methodology is then applied to predict the deformations on an instrumented gas-main in London Clay that was monitored during the construction of tunnels for the Crossrail project at a greenfield site in Hyde Park London. The results show very good agreement between the measured and the predicted strains on the pipe.