pavement design

FLEXIBLE PAVEMENT DESIGN
PAVEMENT LAYERS THICKNESS DESIGN
AASHTO 93
SN = a 1 D 1 + a 2 D 2 m 2 + a 3 D 3 m 3
WHERE
SN
a 1 , a 2 , a 3
D 1 , D 2 , D 3
m 2 , m 3
=
=
=
=
DESIGN STRUCTURAL NUMBER
LAYER COEFFICIENTS REPRESENTATIVE
OF SURFACE (INCLUDING FOAMED
ASPHALT) BASE, AND SUBBASE
COURSES, RESPECTIVELY
ACTUAL THICKNESS OF SURFACE
(INCLUDING FOAMED ASPHALT), BASE,
AND SUBBASE COURSES, RESPECTIVELY
DRAINAGE COEFFICIENTS FOR BASE
AND SUBBASE COURSES, RESPECTIVELY
CHECK FOR FATIGUE
DESIGN STRUCTURAL NUMBER