Table 2.1 Summary of Deflection Basin Parameters
Parameter Definitiona NDT Deviceb
Dynaflect maximum deflection (DMD)
Surface curvature index (SCI)
Base curvature index (BCI)
Spreadability (SP)
Basin slope (SLOP)
Sensor 5 deflection (W )
5
Radius of curvature (R)
Deflection ratio (Qr)
Area, in inches (A)
Shape factors (F F )
1 2
Tangent slope (TS)
DMD = d
1
SCI = d d
1 2
BCI = d d
4 5
SP = ( Idi /5d )x 100
i=1 to 5
SP = ( Idi /4d ) x 100
i=1 to 4
SLOP = d d
1 5
W = d
5 5
R = r2/{2.dm[(dm/dr) 111]}
Qr = r/do
A = 6[1 + 2(d /d ) + 2(d /d ) +
2 1 3 1
F = (d d )/d
1 1 3 2
F = (d d )/d
2 2 4 3
TS = (d dx)/x
Dynaflect
Dynaflect, Road Rater model 400
Dynaflect
Dynaflect
Road Rater model 2008
Dynaflect
Dynaflect
Benkelman beam
FWD, Benkelman beam
(d /d )] Road Rater model 2008
4 1
Road Rater model 2008
a d = deflection; subscripts 1,2,3,4,5 = sensor locations; o = center of load; r = radial distance;
m = maximum deflection; x = distance of tangent point from the point of maximum deflection.
b The NDT device for which the deflection parameter was originally defined.
Source: Uddin et al. (120)