(lb/in.2 )

(kPa)

(lb/in.2 )

(kPa)

6

106

7 x 10 6

7 x 10 6

10

1206 Unfrozen

115 lb/ft 3

5

7 x 10 5

7 x 10 5

105

108

10

105

Calculated σd (lb/in.2 )

4

7 x 10 4

104

7 x 10 4

10

0.5

Density (lb/ft 3)

1.0

High

114 - 117

4.0

Medium

107 - 110

10

104 - 106

Low

14

3

7 x 10 3

7 x 10 3

103

10

100

80

60

40

100

80

60

40

Degree of Saturation (%)

Degree of Saturation (%)

(lb/in.2 )

(kPa)

106

7 x 10 6

Calculated σd (lb/in.2 )

fluence the unfrozen moduli, but to different de-

0.5

grees, depending on the material. The vertical

1.0

7 x 10 5

105

spread in the data points at a particular degree of

5.0

saturation is the result of the material's response

9.0

14

104

7 x 10 4

11a). In the case of the 1206 subgrade and the

class 6 base, it also relates to the variation in den-

sity.

103

7 x 10 3

To show the influence of density in the 1206

subgrade data, Figure 15 differentiates the data

1232 Unfrozen

from three density ranges (high, medium, and low),

102

2

7 x 10

100

90

80

70

60

along with the corresponding predicted moduli

Degree of Saturation (%)

lines.

The effect of stress combinations is shown in

(lb/in.2 )

(kPa)

Figure 16 for the low-density 1206 subgrade data,

106

7 x 10 6

Calculated J2 /τoct (lb/in.2 )

and all of the 1232 subgrade and class 3 special

data. The two subgrades display an inverse rela-

640

330

tionship between modulus and deviator stress; the

117

7 x 10 5

5

class 3 special has a proportional relationship be-

58

10

5

tween modulus and the stress parameter *J*2/*t*oct.

After the resilient modulus testing was com-

pleted, we discovered a calibration error in the

7 x 10 4

104

system used to test the 1206 subgrade in the un-

frozen condition; these data are probably in error.

Testing the 1206 subgrade in the frozen condition

Class 3 Subbase

and all testing on the other materials were done

7 x 10 3

103

with a different system, which passed its calibra-

100

80

60

40

20

Degree of Saturation (%)

tion checks. Comparing test results from the 1206

subgrade with those from other materials indi-

cates that unfrozen *M*r data for the1206 subgrade

may be about an order of magnitude too high.

25