The present methods most widely used for the design of buried flexible pipes have been reviewed in two reports: (1) Krizek,PJ et al entitled "Structural analysis and design of pipe culverts", US Highway Research Board, 1971; and (2) Compston,DG et al entitled "Design and construction of buried thin-wall pipes", CIRIA report no 78, 1978. These methods have a disadvantage in that they consider the various criteria used for the structural performance of a pipe separately, so that, with each criterion based on a different set of assumptions, it is difficult for the designer to assess which one is the most critical for a design. In 1977, the Transport and Road Research Laboratory (TRRL) commissioned Mott Hay and Anderson to develop a more rational approach to the design of buried flexible pipes. This work which included theoretical analyses, model and prototype tests was completed in the early 1980's and limited details of this new design method which provides a unified approach to the prediction of values of deflection, stresses and buckling were published (Gumbel et al 1982, see IRRD 260191). Following this an extensive series of tests was carried out of 300mm diameter metallic or plastic flexible pipes in the pit of the Laboratory to validate the design method. A series of four reports (Contractor Reports Nos 228-231) are being produced in which complete details of the new design method and the supporting studies are given. In this the first of these reports the methods most commonly used in designing buried flexible pipes in Britain are considered. A number of worked examples using the differing design approaches are included as well as an extensive bibliography.

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