Analytical solution for tunnelling-induced response of an overlying pipeline considering gap formation

Soil-pipeline separation due to tunnelling has been certainly substantiated in previous model tests.However,this phenomenon has seldom been considered in current analytical solutions.This study formulates a tensionless Winkler solution that could make allowance for gap formation in soil-pipeline interaction analyses.The solution is validated by comparisons with existing experimental measurements and two recognized analytical solutions.Also,its advantage over an existing Winkler solution is addressed.Further parametric studies reveal that the effects of gap formation on the response of a pipeline rely largely on the tunnel volume loss and the pipeline’s bending stiffness and burial depth.In general,a pipeline’s bending moments and subgrade reaction forces are more susceptible than its deflections to the gap formation.