Basics of Flexible Pipe Structural Design

Abstract

The use of low‐stiffness flexible pipes has increased dramatically in the past few years. The flexibility of these pipes is such that the usual buried pipe models must be used with caution. Several flexible pipe models are reviewed; external loads, pressure rerounding, longitudinal effects, instability (buckling), etc., are discussed, and the importance of some properties of pipe materials and soil is emphasized. The following principles, verified by experience, are proposed: (1) Soil design should supersede deflection in design calculations; (2) deflection should be limited in the long run to generally 5%, strains permitting; (3) the ratio