Table 9.2.2 FASST Default Soil Moisture Properties

Table 9.2.2 FASST Default Soil Moisture Properties.

Residual

Maximum

Van

Genuchten

CI

RCI

CI

θr

θmax

αvG

exponent

Ksat

Coeff.

Soil

nvG

3

c11

c21

c11

c21

Type

(cm/s)

(m /m )

(cm)

0.000262

0.2962

3

22.61

GW

0.01

1.5

0.00010562

0.4032

2.23

22.61

GP

0.01

0.0000672

0.3242

1.23

32.71

GM

0.01

0.000013891

0.344

1.53

23.21

GC

0.01

0.000023612

0.3202

1.253

38.5473

SW

0.01

3.987

0.81500

3.987

0.8150

0.000007412

0.4152

2.53

38.5473

SP

0.01

3.987

0.81500

3.987

0.8150

7.987e-062

0.5262

1.43

68.5473

SM

0.01

8.749

1.1949

12.542

2.955

0.000000292

0.4002

1.53

58.5473

SC

0.01

9.056

1.3566

12.542

2.955

0.000000572

0.4642

1.53

33.91

ML

0.01

10.225

1.565

11.936

2.407

7.7e-082

0.4222

1.343

53.51

CL

0.01

10.998

1.848

15.506

3.530

0.000097222

0.5332

1.343

28.61

OL

0.01

10.977

1.754

17.399

3.584

4.8e-082

0.4572

1.53

32.91

CH

0.01

13.816

5.583

13.686

2.705

1.5e-081

0.5472

1.343

39.01

MH

0.01

12.321

2.044

23.641

5.191

0.0008831

0.8924

1.343

29.31

OH

0.01

13.046

2.172

12.189

1.942

PT

0.000014

0.15

0.70

1.34

38.6

SMSC

7.7e-072

0.3962

1.53

23.5473

(MC)

0.01

9.056

1.3566

12.542

2.955

CLML

1.26e-072

0.3972

1.343

32.91

(CM)

0.01

9.454

1.3850

14.236

3.137

0.000023612

0.3202

1.253

38.5473

EV

0.01

3.987

0.81500

3.987

0.8150

CO,

AS,

RO,

SN

0.0

0.001

0.02

1

Sullivan et al. (1997), p. 28

2

Guymon, et al. (1993), p. 21, 25, 4759

3

Jordan (2000)

4

Yu et al. (1993)

Parameters in Table 9.2.2 are used to calculate the moisture content and resulting strength

of the soil. They are needed for the soil moisture and soil strength subroutines of FASST.

Unlike other models, the soil strength requires moisture content by weight and not by

volume. The moisture/strength equations are a result of curve fitting. They are

CI = exp[c1 + c2 ln( MC )]

(9.4)

RCI = exp[c1 + c2 ln( MC )]

where CI is the cone index, RCI is the rating cone index, and MC is the moisture content

by weight in percent (Sullivan et al. 1997). The rating cone index is used to quantify the

strength of soils after traffic has passed.

The relationship between volumetric moisture content and pressure head is highly

nonlinear. Following the work of van Genuchten (1980) it is

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