Particle Class Proportions

USDA textural class

Curve parameters

% Sand

% Silt

% Clay

$C_u$

$C_c$

$d\left(\mu \text{m}\right)$

$d\ge 5$

$2\le d<5$

$d<2$

$\frac{d_{60}}{d_{10}}$

$\frac{{\left(d_{30}\right)}^2}{d_{10}\times d_{60}}$

NH2

84.5

08.7

06.8

Silty sand

28.51

7.33

NH3

64.4

08.5

23.1

Sandy-clay silt

1625.96

24.50