fundamentals of engineering supplied-reference handbook - Ventech!

Gross Axle Load
HIGHWAY PAVEMENT DESIGN
AASHTO Structural Number Equation
SN = a1D1 + a2D2 +…+ anDn, where
SN = structural number for the pavement
ai = layer coefficient and Di = thickness of layer (inches).
Load Equivalency
Factors
141
Gross Axle Load
kN lb
Single
Axles
Tandem
Axles
kN lb
4.45 1,000 0.00002
187.0 42,000
8.9 2,000 0.00018
195.7 44,000
17.8 4,000 0.00209
200.0 45,000
22.25 5,000 0.00500
204.5 46,000
26.7 6,000 0.01043
213.5 48,000
35.6 8,000 0.0343
222.4 50,000
44.5 10,000 0.0877 0.00688 231.3 52,000
53.4 12,000 0.189 0.0144 240.2 54,000
62.3 14,000 0.360 0.0270 244.6 55,000
66.7 15,000 0.478 0.0360 249.0 56,000
71.2 16,000 0.623 0.0472 258.0 58,000
80.0 18,000 1.000 0.0773 267.0 60,000
89.0 20,000 1.51 0.1206 275.8 62,000
97.8 22,000 2.18 0.180 284.5 64,000
106.8 24,000 3.03 0.260 289.0 65,000
111.2 25,000 3.53 0.308 293.5 66,000
115.6 26,000 4.09 0.364 302.5 68,000
124.5 28,000 5.39 0.495 311.5 70,000
133.5 30,000 6.97 0.658 320.0 72,000
142.3 32,000 8.88 0.857 329.0 74,000
151.2 34,000 11.18 1.095 333.5 75,000
155.7 35,000 12.50 1.23 338.0 76,000
160.0 36,000 13.93 1.38 347.0 78,000
169.0 38,000 17.20 1.70 356.0 80,000
178.0 40,000 21.08 2.08
Note: kN converted to lb are within 0.1 percent of lb shown.
CIVIL ENGINEERING (continued)
Load Equivalency
Single
Axles
25.64
31.00
34.00
37.24
44.50
52.88
Factors
Tandem
Axles
2.51
3.00
3.27
3.55
4.17
4.86
5.63
6.47
6.93
7.41
8.45
9.59
10.84
12.22
12.96
13.73
15.38
17.19
19.16
21.32
22.47
23.66
26.22
28.99