Homework 5
Vehicle Class
Vehicle Count
Flexible LEF
Flexible ESALs
1–2 16302 0.001 16.3 3 3432 0.004 13.7 4 131 0.300 39.3 5 481 0.170 81.8
6–7 515 0.700 360.5 8 824 0.700 576.8
9–13 6915 1.100 7606.5 ADT = 28600 0.304 8695
8695
28600
1-way ADT 2 lanes 3 lanes 4 lanes
5,000 or less 90% 75% 70%
5,000–10,000 80% 70% 65%
10,000–15,000 75% 65% 60%
15,000–20,000 75% 65% 55%
20,000–30,000 70% 60% 50%
30,000–70,000 65% 60% 50%
Estimating Subgrade MR
1500 RM CBRWARNING: Only for fine-grained soils with soaked CBR < 10.
1993 AASHTO Guide
11
Estimating Subgrade MR
0.642555 RM CBRGood for a wide range of soil types
AASHTO MEPDG
12
Asphalt Layer Coefficient
15
0.30
ATB Layer Coefficients
17
0.30
Base Layer Coefficient
19
0.30
0.30
Subbase Layer Coefficients
23