The paper, in its first sections, is concerned with theoretical aspects of the inverse problem solution for a multilayered pavement model for both main current pavement deflection testing arrangements: (a) deflectometer and (b) deflectograph. The solution methods are described that make use of the deflection sensitivity factors associated with changes in layer moduli. These solution procedures served as a basis for developing computer programs DEGARES and BACKLAY for the deflectograph and deflectometer testing, respectively. The standard overlay design method is further described based on current Czech design specifications TP 77 for flexible pavements. The design method applies elements of the theory of reliability. The selected results of the 1998 comparative measurements, organized by the Czech Road Directorate, with four FWD testing devices and two deflectographs having taken part, are then used as a basis for discussing several practical aspects of the pavement performance evaluation and overlay design with conclusion that backcalculation programs must be used with extreme caution and that additional research is needed to further refine the backcalculation process. (A) For the covering abstract see ITRD E104741.


  • English

Media Info

  • Features: References;
  • Pagination: p. 319-6

Subject/Index Terms

Filing Info

  • Accession Number: 00792986
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • ISBN: 83-907304-7-2
  • Files: ITRD
  • Created Date: May 31 2000 12:00AM