PDF] BACKGROUND TO THE THIRD EDITION OF THE BRITISH PORTS ASSOCIATION HEAVY DUTY PAVEMENT DESIGN MANUAL

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Last updated 12 janeiro 2025

PDF] BACKGROUND TO THE THIRD EDITION OF THE BRITISH PORTS ASSOCIATION HEAVY DUTY PAVEMENT DESIGN MANUAL

The Third Edition of the British Ports Association heavy duty pavement design manual has recently been published and for the first time, a radically new way of analysing pavements is incorporated in the design method. The original research upon which the First Edition 1 was based was undertaken in the 1970' s and pavements were analysed by programmabie calculator technology12 This meant that stresses and strains could be calculated accurately at ouly one or two special points in the proposed pavement structnre. The Third Edition includes pavement design charts which are based upon finite element aualysis. This has allowed design to be based upon the concept of Equivalent Single Load. Also, it has allowed the design of the whole pavement can be separated into design of the base and design of the foundation. In making this separation, no accuracy is lost and the design exercise has been greatly simplified such that ouly one Chart is now required for design. That Chart is included in this paper and may be used to proportion the base course of a heavy duty pavement. Table 6 in this paper can then be used to select the pavement foundation according to ground conditions. The resulting pavement should remain serviceable throughout its life. During the last 10 years, a good deal of experience has been gained in the use of Material Conversion Factors or Material Equivalence Factors so that they can now be used as a means of effectively swapping one material for another during the design process. This means that when a design has been produced using the Chart, the designer can generate alternative design solutions using different materials and so investigate a full range of solutions. Table 5 gives Material Conversion Factors for a full range of commonly used base materials. The new Edition differs from previous ones in that Material Conversion Factors were used previously only in overlay design. Overlay design has been deleted from the third Edition: it has been found to be less relevant than was expected to be the case when the First Edition was published in 1984. Difficulties associated with drainage and with· changes in levels have , meant that overlaying existing pavements has failed to become a cost effective solution to: either rehabilitation or strengtheuing of existing pavements