Design Oriented Linear-Equivalent Approach for Evaluating the Effect of Tunneling on Pipelines

The process of tunneling is associated with ground movements which may lead to stressing of nearby existing buried infrastructure, and potentially poses a risk of damage. The need for an effective evaluation method of the potential risk increases with the ongoing expansion of underground space utilization. This paper presents a new approach for evaluating the interaction between an assumed input of greenfield tunneling displacements and an existing buried pipeline. The approach integrates new developments with previous research findings to establish a practical interaction analysis methodology that can be used in design. It involves the use of an elastic-continuum analysis to solve the soil-pipeline interaction together with an iterative calculation of the equivalent stiffness in order to consider soil nonlinearity. A set of simplified closed-form expressions, which can be used to evaluate maximum pipeline bending moments within the suggested framework, are presented in the paper. A comparison of the new method results against centrifuge test data and advanced discrete element-method simulations is presented in the paper. The obtained agreement provides validation of the new method over a wide range of tunneling-induced volume losses and pipeline parameters.