Relative Pavement Bearing Strength Requirements of Aircraft

Procedures and charts are presented to develop index numbers for reporting airfield bearing strength. Upon completion of an assessment of airfield bearing strength by the airfield authority, the results are reported as an index number that is a measure of the airplane effect on the pavement system. For reporting purposes, the airplane variables of wheel load, wheel spacing, and tire pressure, and the pavement variables of type (rigid, flexible, or composite), and subgrade strength characterization (strong, medium, low, and extra low strength) are related by means of two theoretical stress/deflection distributions: Westergaard for rigid pavements and modified Boussinesq for flexible pavements.