Alferink, Bjoerklund, Kallioinen
Design & Testing # 1998 Gothenburg
Over the last 15 years several attempts have been undertaken to establish a design method for plastics pipes (IS0 TC138 WG13) and over the last ten years to establish an unified design method for all buried pipes (CEN TC1641165 JWGI). Several national methods are available and it is shown over the last ten years that it is extremely difficult to come to a consensus about the design of buried pipes, when following a clean and straight mathematical approach. In relation to this, the industry is very much concerned about how to implement methods based on such a mathematical approach in real life projects. Furthermore, the need for one method seems to become more and more important especially now that amongst users the wish for a so-called "non-design" pipe is becoming relevant. A first attempt to establish such a pipe, with the use of "W" classes instead of PN was voted down in the ongoing CEN standardization work for pressure pipes. Amongst other reasons also because of the absence of an unified design method. The critical succesfactor for reaching a general agreement on how to design gravity as well as pressure pipes, has been found to be the existence of comprehensive field data. Of course field data is available, as measured by different organisations and published more then once. Although they potentially form a firm basis for a design method based on experience, these data are not detailed enough to allow an accurate judgement of the more complicated design methods. Therefore TEPPFA and APME sponsored a joint research project with the aim to provide the European experts with these data, and to develop a firm basis for tools to be used to inform customers about the excellent features of thermoplastics pipes for buried applications. This paper reports about the background of the project, the approach taken and the relative place of design versus installation and material capabilities. It presents a design philosophy including all aspects of pipeline design and installation.
