A simplified solution for buried continuous pipe rehabilitated by liner under the effect of surface load and soil void

Underground pipelines play a crucial role in the rapid urbanization of cities. Steel pipelines, renowned for their high strength, durability, and excellent weldability, are extensively employed in water supply systems. However, as these pipelines age, the soil beneath them may experience subsidence, resulting in void formation that can severely threaten the pipeline's integrity and even compromise the surface above. This study investigates the mechanical behavior of steel pipelines rehabilitated with liners, subjected to surface loads and soil voids, based on the principles of elastic foundation beams. The process is thoroughly detailed. Subsequently, the derived analytical model is validated through the finite element method, and the effects of various parameters—such as void width, distance from the void to the load center, load width, soil stiffness, burial depth, pipeline diameter, and pipe wall thickness—on the mechanical performance of the pipeline are explored. The failure limit state of the pipeline is also examined. The findings reveal that when the load center aligns with the void center, liner stress reaches its peak. Liner stress initially increases with void width but gradually stabilizes as it approaches yield stress. Moreover, for pipes with higher diameter-to-thickness ratios, the pipe thickness becomes more critical as stress intensifies.