Alferink, Janson, Olliff
Design & Testing # 1998 Gothenburg
Extensive field trials are being performed in a project sponsored by TEPPFA and APME,to obtain well documented information about the behaviour of buried thermoplastics pipes. as outlined in the paper by Alferink, Bjorklund and Kallioinen (Ref 1). This information is of vital importance to obtain a workable design method for buried pipes. Tests were carried out using different pipe materials (PVC,PE,Steel), different pipe stiffness, buried at depths varying between 1.15 and 3 metres, using clay as well as sand as sidefill, and by installing them in a compacted as well as in a dumped way. Pipe detlection and strain measurements were carried out, when the pipes were loaded by soil, traffic and internal hydrostatic pressure. European design experts were put to work with the soil and pipe parameters, and asked to carry out the design using their own or their national design method. Afterwards, they were provided with the results of the measurements carried out on the pipe as well as on the soil, allowing them to asses their design. Then in December 1997 a workshop took place with those experts to discuss the results and with the intention to obtain a good basis for establishing an unified design method for all buried pipes, and by that assisting current CEN work on the same subject. This paper presents a first glance of the results of the work carried out so far. The results show that consistency between installation and design practice is one of the major factors to be considered. Based on the results as found in the field studies, the authors recommend a design approach which safely predicts the behaviour of buried pipes.