Lateral Resistance of Buried Pipes by Frictional Limit Analysis

Pipelines are vital means of transportation of liquids and gases over large geographical areas. Regarding buried pipes, they are submitted to thermal and mechanical loads due to their support conditions, pipe-soil friction and the surrounding soil mass. Under high compressive loads carried out by these efforts, loss of stability and buckling may occur. Then, the evaluation of soil lateral resistance that will cause a imminent breakout is important. This work aims the analysis of the soil lateral resistance by frictional limit analysis formulation, considering the soil mass as a deformable body and the pipe as a rigid one. An yield function considering material porosity and material friction angle is considered. The soil lateral resistance forces obtained from the proposed formulation are compared to a those ones considering the limit analysis lower bound found in literature. The fully bounded condition observed in most models is also discussed.