Cover Requirement and Stability of Horizontally Bent Buried Pipelines

A method of calculating soil cover requirements for horizontally bent buried pipelines is described. In sequence, the results of a comprehensive three-dimensional finite element analysis are used to develop regression models for two dependent variables: maximum allowed temperature change and minimum overburden height. Other variables considered include the pipe diameter and thickness, the radius and angle of the bend, the internal pressure, the fluid specific weight, and the material used. Relationships among the different variables are determined. Finally, the results are checked with respect to several buckling modes to consider elastic instability conditions.