Title: THE CATALOGUE OF STRUCTURES OF THE DIRECTION OF HIGHWAYS AND FRENCH HIGHWAY TRAFFIC
Abstract: Present methods of structural design, based on a combination of theoretical and empirical considerations, do not seem to be entirely satisfactory for several reasons: They very rarely take account of certain elements of good practice which are essential for the proper behavior of pavements; they do not easily allow for extrapolation to pavements of a new type or to a different environment; they give the designer a false impression of accuracy, whereas in fact they are very imprecise and depend to the highest degree on the quality of the materials and their application. Consequently the idea of a catalogue of structures has arisen, giving possible structures for a certain number of categories of soil and traffic, and giving for these different solutions the advantages and drawbacks liable to be encoutered either at the time of carrying out the work or during the life of the pavement. The catalogue also indicates the required composition of materials and the necessary conditions of performing the work, together with the characteristics of predictable non-destructive testing (deflection, speed of wave propagation, etc...). Structures for overlaying of existing pavements are also included in the catalogue. Where traffic is concerned, account has been taken only of heavy vehicles (without bringing in the notion of equivalent traffic), and 4 classes are proposed, each corresponding to an order of magnitude of the total heavy traffic which the pavement must be able to bear before being totally remade. Subgrades have also been placed in 4 categories, on the basis of the U.S.C.S. classification and in certain cases additional geotechnical characteristics of hydraulic conditions. In the case of overyaling the subgrade categories are replaced by 4 other categories, defined in the light of deflection (overall properties of the existing pavement), where necessary corrected. The structures proposed are then designed taking account of: (1) existing theoretical elements; (2) specific characteristics of the materials used; (3) problems of construction; (4) data available on existing pavements. It is hoped that this catalogue will provide a design tool with much flexibility and one which allows for standardization of structures.
Publication Year: 1972
Publication Date: 1972-09-01
Language: en
Type: article
Access and Citation
AI Researcher Chatbot
Get quick answers to your questions about the article from our AI researcher chatbot