Research Article

Particle-Size Distribution Models for the Conversion of Chinese Data to FAO/USDA System

Table 2

Particle-size distribution models.

NameModel Parameters

Anderson
(AD [8])
b, c, ,

Fredlund4P
(F4P [11])
, , ,
( )

Fredlund3P
(F3P [11])
, ,
( )

Modified logistic growth
(ML [43])
a, b, c

Offset-nonrenormalized
lognormal
(ONL [9])
, 
where

, ,

Offset-renormalized lognormal
(ORL [9])

defined in ONL model]
, ,

Skaggs
(S [12])
, 
where
= 0.002 mm for T1; = 0.001 mm for T2, 
T3; : fraction <
u, c

van Genuchten type
(VG [7])

where
, n

van Genuchten type modified
(VGM [34])
, 
where ; 
, fraction of minimum particle size
a, n

Weibull
(W [10])
, 
where
, for T1;  
, for T2, T3
a, b, c,

d: particle diameter in mm.
: error function.