FINITE-ELEMENT ANALYSIS OF CONCRETE SLABS AND ITS IMPLICATIONS FOR RIGID PAVEMENT DESIGN

A FINITE-ELEMENT METHOD PROGRAMMED FOR A HIGH-SPEED COMPUTER WAS DEVELOPED FOR DETERMINING THE STRESSES IN CONCRETE METHOD IS BASED ON THE CLASSICAL THEORY OF THIN PLATES ON WINKLER FOUNDATIONS AND YIELDS NUMERICAL RESULTS THAT CHECK CLOSELY WITH OTHER AVAILABLE SOLUTIONS AS WELL AS WITH THE EXPERIMENTAL MEASUREMENTS FROM THE AASHO ROAD TEST. ALTHOUGH A SINGLE VALUE OF THE MODULUS OF SUBGRADE REACTION CAN BE SELECTED TO PREDICT APPROXIMATELY THE STRESSES FOR VARIOUS SLAB THICKNESSES AND AXLE LOADS, IT WAS FOUND THAT, UNDER A GIVEN AXLE LOAD, A BETTER AGREEMENT BETWEEN THEORETICAL AND EXPERIMENTAL RESULTS COULD BE OBTAINED IF GREATER SUBGRADE MODULI WERE USED FOR THICKER PAVEMENTS, A FACT CONTRIBUTING TO THE NONLINEAR BEHAVIOR OF SUBGRADE SOILS. NUMERICAL RESULTS ARE PRESENTED TO ILLUSTRATE THE EFFECT OF LOADING POSITION, LOAD TRANSFER, AND LOSS OF SUBGRADE CONTACT ON CRITICAL STRESSES IN RIGID PAVEMENTS. WHEN LOAD TRANSFER IS PROVIDED AT THE TRANSVERSE JOINT, THE MOST CRITICAL STRESS IN HIGHWAY PAVEMENTS OCCURS WHEN THE LOAD IS NEAR THE EDGE AND FAR FROM THE JOINT. IT IS SUGGESTED THAT THE EDGE STRESS, INSTEAD OF THE STRESS AT THE JOINT, BE USED FOR THE DESIGN OF HIGHWAY PAVEMENTS.