CEN/TR 1295-3:2007

Foreword
Introduction
1 Scope
2 References
3 Structural design issues
  3.1 Soils
  3.2 Pipe materials
  3.3 Types of loading
4 Principles used in Annex A (Option 1) and Annex B (Option 2)
  4.1 General
  4.2 Principles used in Annex A (Option 1)
  4.3 Principles used in Annex B (Option 2)
5 Synopsis
Annex A Structural design of buried pipelines - Option 1
      A.1 General
      A.2 Terms and definitions
      A.3 Symbols
      A.4 Principle
      A.5 Installation conditions
      A.6 Initial loads
      A.7 Soil parameters
      A.8 Load distributions
      A.9 Loads acting on the pipe
      A.10 Internal pressure
      A.11 Pipe deflection
      A.12 Analysis of bending moments, normal forces,
           stresses and strains
      A.13 Longitudinal effects
      A.14 Stability analysis (only required for flexible pipes)
      A.15 Calculated factors of safety from the design procedure
           and analysis
      A.16 Minimum factors of safety and failure probability
Annex AA Classification of soils
Annex AB Factors of safety and failure probability
Annex AC Soil mechanics background on soil moduli
Annex AD General remarks on stability analyses for buried pipes
Annex AE Finite element analysis
Annex AF Detailed notes relative to longitudinal effects
Annex AG Flowchart and worked examples
Annex B Structural design of buried pipelines - Option 2
      B.1 General
      B.2 Terms and definitions
      B.3 Symbols
      B.4 Principle
      B.5 Pipe parameters
      B.6 Installation conditions and related calculation parameters
      B.7 Stiffness criterion
      B.8 Loadings
      B.9 Load and interaction pressure distributions
      B.10 Buckling
      B.11 Ring deflection
      B.12 Bending moments, axial forces, stresses and strains
      B.13 Verification of safety in use
      B.14 Summary of design procedures and relevant verifications
      B.15 Analysis of longitudinal effects
      B.16 Analysis of seismic action
Annex BA Classification of soils
Annex BB Factors of safety and failure probability
Annex BC Background on soil moduli
Annex BD Rigid, semi-rigid and flexible pipes - A proposal for a
         definition of ranges of system behaviour
Annex BE Background of the Marston method
Annex BF Longitudinal effects - Notes of B.15
Annex BG Worked examples
Annex C Classification of soils
Annex D Factors of safety and failure probability
      D.1 Rudiments of the theory of probabilistic reliability
      D.2 Analysis of reliability of buried piping systems
      D.3 Scatter of parameters
      D.4 Results of the analysis
Annex E Longitudinal effects
      E.1 Longitudinal effects
      E.2 Failure behaviour due to longitudinal effects
      E.3 Failure modes
      E.4 Longitudinal effects
Annex F Detailed notes relative to longitudinal effects
        (according to A.13 and B.15)
Bibliography

This document specifies calculation methods for the structural design of water supply pipelines, drains and sewers, and other water industry pipelines, whether operating at atmospheric, greater or lesser pressure.It applies for the structural design of buried piping systems, made from all materials used for the conveyance of fluids under pressure or gravity conditions.Pipes to be designed for installations in abnormal or unusual conditions, e.g. in quick soils or a marine sea bed, are not covered by this document, it may require special engineering.The design of very large diameter pipe installations may require considerations to be given to other additional parameters, e.g. the homogeneity of the surrounding soil.The design method is intended to be used for pipes operating at different temperatures provided that the corresponding temperature re-rating factors for the relevant pipe properties are used as specified in the referring standard(s). Nevertheless, high services temperatures may require an additional analysis of the longitudinal stresses and strains and/or a special design of the joints.