Plastic pipework is used underground, in road building, water supply systems and in building construction, either externally mounted or embedded in the concrete structure. Plastic conduit provides protection for communication and power cables, and plastic piping is used to deliver products such as water and gas, and for drainage pipes for waste water. Depending on the application, the pipework may or may not be pressurized. Normally, such pipework meets the demands placed on it perfectly adequately, but under certain conditions excessive deformation and buckling may occur which cause operational problems. This may have serious consequences for the entire network in question. Repairing such damage is difficult, time consuming and expensive. In Switzerland alone, the annual cost of such work is estimated to be in the region of up to one hundred million francs.

Denting and buckling of piping, and its consequences, can be avoided by correct, engineering-based planning of the system. For this to be possible in addition to professional expertise it is necessary to have detailed knowledge of the properties of the materials used and characteristics of the system under consideration.

The aim of the course offered by the Empa, entitled “Dimensioning plastic pipework to prevent external pressure damage”, was to disseminate the basic ideas and necessary engineering data to allow the correct dimensioning, layout and system analysis of plastic piping networks, and to apply this knowledge interactively using real-life examples. The participants, mainly civil engineering planners and stress analysts, learnt a great deal about the materials used and their mechanical properties. They were given an overview of the fundamentals of the dimensioning process and were introduced to the practical aides used to make calculation easier. In addition, time was set aside for discussing and analyzing relevant real-life cases of damage. Working in groups, the participants carried out computer coursework consisting of examples of dimensional calculations with comprehensive stress analysis performed according to the latest standards such as SN ISO 1295-1 (Sia 190.101).

The next course will be held on May 11th 2005.

Contact person for further technical information and course data:

Prof. Dr. Mehdi Farshad, Plastics/Composites Lab., Tel. +41 44 823 44 91, E-mail: mehdi.farshad@empa.ch

Peter Flüeler, Plastics/Composites Lab., Tel. +41 44 823 41 14, E-mail: peter.flueler@empa.ch