A WORKING SYSTEMS MODEL FOR RIGID PAVEMENT DESIGN

IN 1971, A CONCEPTUAL SYSTEMS ANALYSIS WAS PRESENTED AT THE 50TH ANNUAL MEETING OF THE HIGHWAY RESEARCH BOARD BY KHER ET AL. THE PRESENT PAPER DESCRIBES THE EQUATIONS AND METHODS OF SOLUTION THAT ARE REQUIRED TO PERFORM THE SYSTEMS ANALYSIS OUTLINED IN THAT PAPER. A COMPUTER PROGRAM SOLVES THE MATHEMATICAL MODELS BY USING SYSTEMS ANALYSIS CONCEPTS PREVIOUSLY DESCRIBED BY THE AUTHORS. ANALYSIS TECHNIQUES, REQUIRED INPUTS, AND THE OUTPUT OBTAINED ARE ALSO DESCRIBED. A PRELIMINARY SYSTEM EVALUATION HAS BEEN ATTEMPTED THROUGH A SENSITIVITY ANALYSIS OF IMPORTANT VARIABLES AFFECTING RIGID PAVEMENT DESIGN. THE COMPUTER PROGRAM IS BASED ON A COMPREHENSIVE ECONOMIC ANALYSIS OF VARIOUS PHASES OF RIGID PAVEMENT DESIGN AND MANAGEMENT. IN GENERAL, PAVEMENT AND OVERLAY TYPE, REINFORCEMENT DESIGN, JOINT DETAILING, SUBBASE AND CONCRETE THICKNESS DESIGN, AND MAINTENANCE AND OVERLAYING ARE THE IMPORTANT PHASES THAT ARE ANALYZED TO OPTIMIZE FOR THE BEST POSSIBLE DESIGN CONFIGURATION. THE PROGRAM USES 117 DIFFERENT INPUT VARIABLES AND GIVES THE OPTIMAL DESIGN AND 23 NEARLY OPTIMAL DESIGNS IN INCREASING ORDER OF TOTAL OVERALL COST. THE ORDERED CHOICE PROVIDES THE DESIGNER OR THE ADMINISTRATOR WITH INFORMATION NEEDED IN MAKING A RATIONAL PAVEMENT DESIGN DECISION.