A general slip-line field solution for the ultimate bearing capacity of a pipeline on drained soils

• A general slip-line field solution of the bearing capacity of a pipeline on drained soils.
• Slip-line stress field for a pipeline foundation obeying Mohr–Coulomb criterion.
• Slip-line stress field matches well with numerical incremental-displacement field.
• Parametric studies for understanding failure mechanism of the pipeline foundation.

An accurate evaluation of the ultimate bearing capacity of a cylindrical foundation is crucial for predicting pipe–soil interaction behaviors. A general slip-line field solution is derived for the ultimate bearing capacity of a pipeline on the drained soil obeying Mohr–Coulomb criterion. The slip-line field around the pipeline matches well with the corresponding plastic incremental-displacement field simulated by utilizing finite element analysis. Parametric studies indicate that as the internal friction angle of the soil approaches zero, the derived bearing capacity factors for the pipeline on the drained soil limit to those for the pipeline on the undrained soil obeying Tresca criterion. The bearing capacity factors for a fully-smooth pipeline then limit to those for a conventional rectangular strip-footing while the pipeline embedment approaches zero. Moreover, the dimensionless collapse load increases with increasing the pipeline embedment and the pipe–soil interfacial friction.