Table 1 (cont'd).
B. Unfrozen condtion.
Std
lb/in.2)
r2
Material
Equation (Mr in
error
n
Clay subgrade sample 1206 (565)
Mr = 1, 597, 000 f (S)-2.63 f (γ )14.42 f3 (σ)-0.257
Never frozen
655
0.82
0.251
Clay subgrade sample 1232 (566)
Mr = 1.518 1030 f (S)-13.85 f3 (σ)-0.272
451
0.95
0.328
Never frozen
Class 3 "stockpile"
Mr = 283, 300 f (S)-1.003 f2 (σ)0.206
408
0.86
0.520
Thawed
Class 4 (taxiway A subbase)
Mr = 8.946 108 f (S)-3.026 f2 (σ)0.292
149
0.86
0.168
Thawed
Class 5 (dense graded stone)
Mr = 382, 400 f (S)-0.8759 f2 (σ)0.1640
64
0.77
0.164
Thawed
Class 6 "stockpile"
Mr = 1, 391 f (S)-0.507 f (γ )4.04 f1(σ)0.608
492
0.79
0.232
Thawed
0.0193 f1(σ)
Mr = 5, 257 f (S)-0.486 f (γ )4.05 e
Thawed
492
0.76
0.249
Notes:
f(wuv) = wuv/wo
n
= number of test points
r2
wuv = volumetric unfrozen water content
=
coefficient of determination
Mr
=
resilient modulus
σ
stress (lb/in.2)
f(S)
S/So
=
=
f1(σ) =
J1/σo
S
=
degree of saturation (%)
f2(σ) =
(J2/toct)/σo
So
=
1.0 %
γ /γ
f(γ)
τoct/σo
f3(σ) =
=
d 0
γ
σo =
dry density (Mg/m3)
1.0 lb/in.2
d =
γ
1.0 Mg/m3
bulk stress (lb/in.2)
J1 =
0 =
3σ3 + σd
wug/wt
J1 =
f(wu) =
2nd stress invariant (lb/in.2)
wug =
J2 =
gravimetric unfrozen water content
3σ32 + 2σ3σd
J2 =
wt =
gravimetric total water content
τoct =
octahedral shear stress (lb/in.2)
f (wu-g ) =
wug/wo
(
)
2 3 σd
τoct =
wo =
unit water content (1.0)
*Output from equations can be converted to kPa by multiplying by 6.895.
In this relation, failure occurs when D equals or
summation of cycle ratios, referred to as Miner's
exceeds 1.0. Thus, for a section to last its design
rule, which may be stated as:
life, the value of D cannot accumulate to 1.0 until
i
ni
the design period expires.
=D
∑
(1)
The value ni relates to the design traffic, or
i =1 Ni
applications, in 8165-kg (18,000-lb) equivalent
where ni = number of applications at strain level i
standard axle loadings (ESALs). For the two ini-
Ni = number of applications to cause fail-
tial modeling series of this study, traffic was an-
ure at strain level i, based on damage
ticipated to be 2,815,000 ESALs during a 5-yr
model predictions
period. Loadings were applied on a daily basis at
a constant rate of 1542 ESALs per day. In the
D = total cumulative damage.
7
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