Analytical solution for upheaval buckling of shallow buried pipelines in inclined cohesionless soil

Abstract

Upheaval buckling of pipelines can occur under thermal expansion and differential ground settlement. Research on this phenomenon has usually assumed the pipes are buried in horizontal ground. For long-distance transmission pipelines across mountainous areas, the ground surface is commonly inclined. Based on the Rankine earth pressure theory and Mohr-Coulomb failure criterion, analytical formulae for calculating the peak uplift resistance and the slip surface angles for a buried pipe in inclined ground are presented in this paper. Analyses indicate that the slip surfaces in inclined ground are asymmetric and rotate towards the downhill side. Under a shallow burial depth, the failure plane angle is highly impacted by the ground inclination. When the embedment ratio (H/D) is more than 4, the influence of the ground slope on the failure plane angle is negligible. The peak uplift resistance reduces in inclined ground, especially when H/D is less than 1. Finally, a simple equation considering the impact of ground inclination is proposed to predict the peak uplift resistance.