Flexible Pipe Design Revisited

Prevost, Robert C.; ,

Flexible Pipe Design Revisited

by Robert C. Prevost,

Document Type: Proceeding Paper

Part of: Pipeline Design and Installation

Abstract:

An overwhelming soil factor in the Iowa formula and random deformations at installation affords soil a prominent role in flexible pipe; this, together with a maximal deflection rule make obsolete deflection calculation for design purposes. Buckling sets this maximal deflection at 5% and determines the pipe minimal stiffness. 'Dynamic buckling' is the preferred model because it rests upon established rationale and minimal assumptions about soil/pipe interaction because it is the lower envelope of field and lab experience, and fits well with extant recommendations; alternative 'composite' models do not fit soil behaviour, and allow too weak pipe in stiff soils. Classical theory, advanced through 'harmonic analysis' and confirmed by experience, evidences the primary role of the factors E'/S and p/S, the ratios of the modulus of earth reactions and internal pressure to pipe stiffness.

Return to search