4. Buried piping

4.1 General

The design is based on the same principles as for overhead or underground piping, taking into account the particularities of the environment in which it will be laid.

Wall thickness is calculated by distinguishing between standard and non-standard cases.

The standard case is that of backfilled trench laying, for which the thickness is calculated taking into account internal pressure and external pressure due to earth pressure.

Non-standard cases correspond to so-called special points:

• areas through which machinery passes if the pipe is not protected by a sheath or slab;

• subsidence zones ;

• ...