Analytical solutions for tunnelling-induced response of two overlying pipelines

Nowadays, it is increasingly common to construct new tunnels beneath existing buried pipelines in urban areas. An accurate prediction of the response of buried pipelines to tunnelling is essential for their protection. In this paper, two analytical solutions incorporating the elastic-continuum model and the Pasternak model, respectively, are formulated to estimate the deflections and bending moment of two neighboring pipelines situated above a newly constructed tunnel. The solutions are validated by both model tests and field observations. Parametric studies show that the effects on the pipelines' deflections and bending moment rely largely on their horizontal distance, bending stiffness, and burial depth. The pipelines are more influenced by their interactions in terms of bending moment than deflections.