RELIABILITY CONCEPTS APPLIED TO THE TEXAS FLEXIBLE PAVEMENT SYSTEM

THE FLEXIBLE PAVEMENT SYSTEM (FPS) IS A WORKING PAVEMENT DESIGN SYSTEM IN TRIAL USE BY THE TEXAS HIGHWAY DEPARTMENT. FPS UTILIZES A SYSTEMS APPROACH TO THE PAVEMENT DESIGN PROCESS BY CONSIDERING ALL PHASES OF DESIGN. CONSTRUCTION, AND IN-SERVICE PERFORMANCE TO ARRIVE AT AN ACCEPTABLE PAVEMENT DESIGN. THE WORKING SYSTEM IS COMPUTERIZED AND USES MORE THAN 50 INPUTS. THE OUTPUTS IS AN ARRAY OF POSSIBLE PAVEMENT DESIGN STRATEGIES BASED ON TOTAL OVERALL COSTS. TRIAL IMPLEMENTATION OF FPS IN THE TEXAS HIGHWAY DEPARTMENT HAS SHOWN A DEFINITE NEED TO CONSIDER THE STOCHASTIC NATURE OF MANY OF THE VARIABLES USED IN PAVEMENT DESIGN. THIS PAPER DESCRIBES HOW THE UNCERTAINTY OF ESTIMATION OF VARIABLES LIKE TRAFFIC OR THE HIGHLY VARIABLE DEFLECTIONS ALONG A HIGHWAY PAVEMENT CAN BE CONSIDERED IN A COMPREHENSIVE DESIGN PROCEDURE TO MAKE IT POSSIBLE TO DETERMINE DESIGN RELIABILITY. RELIABILITY IS DEFINED AS THE PROBABILITY THAT THE PAVEMENT WILL HAVE AN ADEQUATE SERVICEABILITY LEVEL FOR A SPECIFIED DESIGN PERFORMANCE PERIOD. CONSIDERED IN THIS RELIABILITY ANALYSIS ARE VARIABILITY ASSOCIATED WITHIN A PROJECT SUCH AS MATERIAL PROPERTIES, THICKNESSES, AND STRENGTHS; VARIABILITY BETWEEN ASSUMED DESIGN VALUES AND THOSE ACTUALLY CONSTRUCTED OR UNDER WHICH THE PAVEMENT WILL BE SUBJECTED DURING ITS DESIGN LIFE (TRAFFIC AND ENVIRONMENT); AND VARIABILITY DUE TO LACK OF FIT OF THE EMPIRICAL EQUATIONS USED IN THE STRUCTURAL SUBSYSTEM. SIGNIFICANT SOURCES OF ERROR WERE FOUND ASSOCIATED WITH ALONG-THE-ROADWAY VARIATION AS MEASURED BY DEFLECTION AND WITH THE LACK-OF-FIT ERROR OF THE STRUCTURAL DESIGN EQUATIONS. SIGNIFICANT ERROR WAS FOUND TO BE ASSOCIATED WITH THE VARIATIONS IN INITIAL SERVICEABILITY INDEX AND ESTIMATED TRAFFIC LOADINGS.

Media Info

  • Media Type: Print
  • Features: Figures; References;
  • Pagination: pp 146-161
  • Monograph Title: Pavement technology
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00206044
  • Record Type: Publication
  • Files: TRIS, TRB
  • Created Date: May 15 1973 12:00AM