CEN/TC 165/WG 12 - Structural design of buried pipelines

This standard specifies the requirements for the structural design of water supply pipelines, drains and sewers, and other water industry pipelines, whether operating under atmospheric, greater of lesser pressure. In addition, this standard   gives guidance on the application of the established methods of design used in CEN member countries at the time of preparation of the standard. - The Decision was decided for Annex B only. -

This Technical Report lists the parameters for the reliability of the structural design of buried water and wastewater pressure pipelines, drains and sewers.
The reliability of the design of buried pipelines is based on the selection of appropriate design parameters for a chosen design method. This document identifies the parameters appropriate to the chosen design method, which should all be clearly stated.
This Technical Report does not aim to specify the requirements for the structural design of water and wastewater pressure pipelines, drains and sewers. EN 1295 1 “Structural design of buried pipelines under various conditions of loading — Part 1: General requirements” defines these requirements.
This Technical Report does not apply for offshore laying, pipes supported on piles, no dig pipelines, or laid above ground. Supplementary considerations need to be taken into account for these specific installations.
Special situations (e.g. landslide, earthquake, fire) are outside the scope of this document.
Design parameters for calculation of longitudinal effects (including bending moments, shear forces and tensile forces resulting for example from non uniform bedding and thermal movements and, in the case of pressure pipelines, from Poisson's contraction and thrust at change of direction or cross-section) are not covered in this document.

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.

In addition to EN 1295-1, this Technical Report gives additional guidance when compared with EN 1295-1 on the application of the nationally established methods of design declared by and used in CEN member countries at the time of preparation of this document (see informative Annex A).
This Technical Report is an important source of design expertise, but it cannot include all possible special cases, in which extensions or restrictions to the basic design methods may apply.
Since in practice precise details of types of soil and installation conditions are not always available at the design stage, the choice of design assumptions is left to the judgement of the engineer. In this connection the document can only provide general indications and advice.

This standard specifies the requirements for the structural design of water supply pipelines, drains and sewers, and other water industry pipelines, whether operating under atmospheric, greater of lesser pressure. In addition, this standard   gives guidance on the application of the established methods of design used in CEN member countries at the time of preparation of the standard.