Geotechnical Aspects of Pavements Reference Manual
Text Versions Of Graphs and Images
Alternative Text for Figure 3-6
Figure 3-6. Approximate pavement cost for varying subgrade support conditions (B.Vandre, personal communication).
Cost per 1000 Square Yards of Surface Area (Rounded to Closest $0.05K) |
| Million ESALs | 0.10 | 0.50 | 1.00 | 5.00 | 10 | 15 | 20 |
Asphalt | CBR=1 | 4.40 | 5.85 | 6.65 | 8.80 | 9.85 | 10.65 | 11.00 |
Base / Granular Borrow | CBR=2 | 5.80 | 6.85 | 7.35 | 8.55 | 9.15 | 9.60 | 9.80 |
CBR=3 | 4.40 | 5.15 | 5.50 | 6.45 | 6.95 | 7.45 | 7.60 |
CBR=4 | 3.65 | 4.20 | 4.55 | 5.35 | 5.75 | 6.20 | 6.35 |
CBR=5 | 3.10 | 3.55 | 3.80 | 4.40 | 4.75 | 5.10 | 5.25 |
CBR=6 | 2.75 | 3.10 | 3.30 | 3.80 | 4.05 | 4.30 | 4.45 |
CBR=7 | 2.00 | 2.55 | 2.75 | 3.35 | 3.60 | 3.90 | 4.00 |
CBR=8 | 1.80 | 2.15 | 2.25 | 2.70 | 2.95 | 3.20 | 3.40 |
CBR=9 | 1.80 | 2.00 | 2.05 | 2.35 | 2.50 | 2.70 | 2.80 |
[ Return To Figure 3-6 ]
Alternative Text for Figure 4-19
Figure 4-19. Particle size limit by different classifications systems.
Comparison of Particle Size Limit by the AASHTO and Unified Soil Classification Systems |
Grain Size (mm) |
Sieve |
Unified |
AASHTO |
0.010 | | Silt and Clay | Silt and Clay |
0.075 | No. 200 |
0.100 | | Sand | fine | Sand | fine |
0.425 | No. 40 |
1.000 | | medium | coarse |
2.000 | No. 10 |
4.750 | No. 4 | coarse | |
10.000 | | Gravel | fine | Gravel |
19.000 | 3/4" |
76.000 | 3" | coarse |
[ Return To Figure 4-19 ]
Alternative Text for Figure 5-17
Figure 5-17. Correlations between subgrade resilient modulus and other soil properties (1 psi = 6.9 kPa; from Huang, 1993, after Van Til et al., 1972).
S, Soil Support Value | Modulus, MR (psi) | R Value (CA) | Modulus, MR (psi) | R Value (WA) | Modulus, MR (psi) | CBR (KY) | Modulus, MR (psi) | TX triaxial class | Modulus, MR (psi) | Group Index | Modulus, MR (psi) |
(X.X) = Estimated Value
NOTE: Soil properties values are approximate and estimated based on the log scale of Subgrade Resilient Modulus, MR, from the original figure included in the FHWA 05-037, May 2006, NHI Course No. 132040, Geotechnical Aspects of Pavements Reference Manual/Participant Workbook
|
10.0 | 40,000 | 90 | 47,000 | 90 | 47,500 | 100 | 44,000 | 2.0 | 40,000 | 0 | 10,000 |
9.5 | 34,000 | 85 | 40,000 | 85 | 41,000 | 95 | 42,500 | (2.5) | 30,000 | (2.5) | 8,800 |
9.0 | 27,000 | 80 | 34,000 | 80 | 35,800 | 90 | 41,000 | 3.0 | 23,000 | 5 | 7,200 |
8.5 | 22,000 | 75 | 28,000 | 75 | 29,100 | 85 | 40,000 | (3.5) | 16,000 | (7.5) | 6,000 |
8.0 | 19,000 | 70 | 27,500 | 70 | 25,000 | 80 | 39,000 | 4.0 | 11,300 | 10 | 5,000 |
7.5 | 16,000 | 65 | 20,000 | 65 | 21,200 | 75 | 37,000 | (4.5) | 7,400 | (12.5) | 4,300 |
7.0 | 13,500 | 60 | 17,000 | 60 | 18,000 | 70 | 36,000 | 5.0 | 4,800 | 15 | 3,700 |
6.5 | 11,300 | 55 | 14,400 | 55 | 15,500 | 65 | 33,800 | (5.5) | 3,200 | (17.5) | 3,200 |
6.0 | 9,400 | 50 | 12,200 | 50 | 13,400 | 60 | 31,200 | 6.0 | 2,080 | 20 | 2,500 |
5.5 | 7,900 | 45 | 10,100 | 45 | 11,500 | 55 | 29,200 | |
5.0 | 6,400 | 40 | 8,800 | 40 | 9,600 | 50 | 27,900 |
4.5 | 5,200 | 35 | 7,400 | 35 | 8,200 | 45 | 25,400 |
4.0 | 4,400 | 30 | 6,000 | 30 | 6,800 | 40 | 23,900 |
3.5 | 3,700 | 25 | 5,000 | 25 | 4,750 | 35 | 21,500 |
3.0 | 3,000 | 20 | 4,600 | 20 | 4,900 | 30 | 19,800 |
2.5 | 2,700 | 15 | 3,600 | 15 | 4,200 | 25 | 17,000 |
2.0 | 2,080 | 10 | 3,100 | 10 | 3,600 | 20 | 15,000 |
1.5 | 1,700 | 5 | 2,550 | 5 | 3,000 | 15 | 12,000 |
1.0 | 1,460 | 0 | 2,150 | 0 | 2,580 | 10 | 9,600 |
| 9.5 | 9,200 |
9 | 9,000 |
8.5 | 8,600 |
8 | 8,200 |
7.5 | 7,800 |
7 | 7,450 |
6.5 | 7,000 |
6 | 6,600 |
5.5 | 6,200 |
5 | 5,800 |
4.5 | 5,200 |
4 | 4,900 |
3.5 | 4,500 |
3 | 4,100 |
2.5 | 3,500 |
2 | 3,050 |
1.5 | 2,400 |
1 | 1,890 |
[ Return To Figure 5-17 ]
Alternative Text for Figure 5-19
Figure 5-19. Correlations between structural layer coefficient a2 and various strength and stiffness parameters for unbound granular bases (AASHTO, 1993).
CBR (Scale derived by averaging correlations obtained from Illinois) | Structural Coefficient, a sub 2 | R-value (Scale derived by averaging correlations obtained from California, New Mexico and Wyoming) | Structural Coefficient, a sub 2 | Texas Triaxial (Scale derived by averaging correlations obtained from Texas) | Structural Coefficient, a sub 2 | Modulus - 1000 psi (Scale derived on NCHRP project) | Structural Coefficient, a sub 2 |
NOTE: Soil properties values are approximate and estimated based on the scale for Structural Coefficient, a2, from the original figure included in the FHWA 05-037, May 2006, NHI Course No. 132040, Geotechnical Aspects of Pavements Reference Manual/Participant Workbook |
100 | 0.140 | 85 | 0.140 | 2.0 | 0.140 | 30 | 0.140 |
70 | 0.130 | 80 | 0.130 | 2.5 | 0.105 | 25 | 0.120 |
60 | 0.125 | 70 | 0.105 | 3.5 | 0.080 | 20 | 0.095 |
50 | 0.115 | 60 | 0.085 | 4.0 | 0.055 | 15 | 0.070 |
40 | 0.105 | 50 | 0.060 | |
30 | 0.095 | |
20 | 0.070 |
[ Return To Figure 5-19 ]
Alternative Text for Figure 5-20
Figure 5-20. Correlations between structural layer coefficient a2 and various strength and stiffness parameters for cement-treated granular bases (AASHTO, 1993).
Unconfined Compressive Strength (psi) 7 day break (Scale derived by averaging correlations from Illinois, Louisiana and Texas) | Structural Coefficient, a sub 2 | Modulus - 1000 psi (Scale derived on NCHRP project) | Structural Coefficient, a sub 2 |
NOTE: Soil properties values are approximate and estimated based on the scale for Structural Coefficient, a2, from the original figure included in the FHWA 05-037, May 2006, NHI Course No. 132040, Geotechnical Aspects of Pavements Reference Manual/Participant Workbook |
1000 | 0.250 | 10 | 0.265 |
800 | 0.220 | 9 | 0.240 |
600 | 0.190 | 8 | 0.215 |
400 | 0.155 | 7 | 0.190 |
200 | 0.125 | 6 | 0.150 |
| 5 | 0.115 |
[ Return To Figure 5-20 ]
Alternative Text for Figure 5-21
Figure 5-21. Correlations between structural layer coefficient a2 and various strength and stiffness parameters for bituminous-treated granular bases (AASHTO, 1993).
Marshall Stability, lb. (Scale derived by correlation obtained from Illinois) |
Structural Coefficient, a sub 2 |
Modulus - 1000 psi (Scale derived on NCHRP project) |
Structural Coefficient, a sub 2 |
NOTE: Soil properties values are approximate and estimated based on the scale for Structural Coefficient, a2, from the original figure included in the FHWA 05-037, May 2006, NHI Course No. 132040, Geotechnical Aspects of Pavements Reference Manual/Participant Workbook |
1900 | 0.330 | 4 | |
1800 | 0.320 | 3 |
1700 | 0.305 | 2.5 |
1600 | 0.295 | 2 |
1500 | 0.285 | 1.5 |
1400 | 0.270 | 1 |
1300 | 0.260 | 4.0 | 0.335 |
1200 | 0.250 | 3.0 | 0.275 |
1100 | 0.240 | 2.5 | 0.250 |
1000 | 0.230 | 2.0 | 0.220 |
900 | 0.215 | 1.5 | 0.190 |
800 | 0.205 | 1.0 | 0.125 |
700 | 0.190 | |
600 | 0.180 |
500 | 0.170 |
400 | 0.160 |
300 | 0.145 |
200 | 0.125 |
100 | 0.090 |
0 | 0.065 |
[ Return To 5-21 ]
Alternative Text for Figure 5-22
Figure 5-22. Correlations between structural layer coefficient a3 and various strength and stiffness parameters for unbound granular subbases (AASHTO, 1993).
CBR (Scale derived by averaging correlations obtained from Illinois) |
Structural Coefficient, a sub 3 |
R-value (Scale derived by averaging correlations obtained from California, New Mexico and Wyoming) |
Structural Coefficient, a sub 3 |
Texas Triaxial (Scale derived by averaging correlations obtained from Texas) |
Structural Coefficient, a sub 3 |
Modulus - 1000 psi (Scale derived on NCHRP project) |
Structural Coefficient, a sub 3 |
NOTE: Soil properties values are approximate and estimated based on the scale for Structural Coefficient, a2, from the original figure included in the FHWA 05-037, May 2006, NHI Course No. 132040, Geotechnical Aspects of Pavements Reference Manual/Participant Workbook |
100 | 0.140 | 90 | 0.140 | 2.0 | 0.140 | 20 | 0.135 |
70 | 0.130 | 80 | 0.130 | 3.0 | 0.120 | 15 | 0.110 |
50 | 0.125 | 70 | 0.120 | 4.0 | 0.085 | 14 | 0.105 |
40 | 0.120 | 60 | 0.105 | 5.0 | 0.045 | 13 | 0.095 |
30 | 0.110 | 50 | 0.090 | | 12 | 0.090 |
20 | 0.095 | 40 | 0.070 | 11 | 0.085 |
10 | 0.080 | 30 | 0.055 | 10 | 0.075 |
5 | 0.050 | 25 | 0.050 | |
[ Return To Figure 5-22 ]
Alternative Text for Figure 5-27
Figure 5-27. Correction of effective modulus of subgrade reaction for potential loss of subbase support (AASHTO, 1993).
LS = 0 Little or No Erosion | LS = 1.0 | LS = 2.0 | LS = 3.0 Most Erosion |
Effective Modulus of Subgrade Reaction, k (pci) | Effective Modulus of Subgrade Reaction, k (pci) - Corrected for Potential Loss of Support | Effective Modulus of Subgrade Reaction, k (pci) | Effective Modulus of Subgrade Reaction, k (pci) - Corrected for Potential Loss of Support | Effective Modulus of Subgrade Reaction, k (pci) | Effective Modulus of Subgrade Reaction, k (pci) - Corrected for Potential Loss of Support | Effective Modulus of Subgrade Reaction, k (pci) | Effective Modulus of Subgrade Reaction, k (pci) - Corrected for Potential Loss of Support |
NOTE: Corrected keff values are approximate and estimated based on the original figure included in the FHWA 05-037, May 2006, NHI Course No. 132040, Geotechnical Aspects of Pavements Reference Manual/Participant Workbook |
1 | 1.0 | 1.30 | 1.0 | 1.45 | 1.0 | 2 | --- |
2 | 2.0 | 2 | 1.5 | 2 | 1.4 | 2.20 | 1.0 |
3 | 3.0 | 3 | 2.2 | 3 | 1.7 | 3 | 1.2 |
4 | 4.0 | 4 | 2.8 | 4 | 2.0 | 4 | 1.5 |
5 | 5.0 | 5 | 3.3 | 5 | 2.3 | 5 | 1.7 |
6 | 6.0 | 6 | 3.9 | 6 | 2.7 | 6 | 1.8 |
7 | 7.0 | 7 | 4.4 | 7 | 2.9 | 7 | 1.9 |
8 | 8.0 | 8 | 4.8 | 8 | 3.2 | 8 | 2.0 |
9 | 9.0 | 9 | 5.3 | 9 | 3.4 | 9 | 2.2 |
10 | 10.0 | 10 | 5.9 | 10 | 3.6 | 10 | 2.4 |
20 | 20.0 | 20 | 10.5 | 20 | 5.7 | 20 | 3.4 |
30 | 31.5 | 30 | 15.5 | 30 | 7.2 | 30 | 4.1 |
40 | 41.5 | 40 | 19.0 | 40 | 8.8 | 40 | 4.8 |
50 | 52.0 | 50 | 22.5 | 50 | 10.0 | 50 | 5.3 |
60 | 62.0 | 60 | 26.0 | 60 | 11.5 | 60 | 6.0 |
70 | 72.0 | 70 | 29.5 | 70 | 13.5 | 70 | 6.5 |
80 | 83.0 | 80 | 33.0 | 80 | 14.5 | 80 | 6.9 |
90 | 94.0 | 90 | 36.0 | 90 | 15.7 | 90 | 7.3 |
100 | 105.5 | 100 | 40.0 | 100 | 16.7 | 100 | 7.7 |
200 | 208.5 | 200 | 69.0 | 200 | 25.0 | 200 | 11.5 |
300 | 314.0 | 300 | 100.0 | 300 | 32.0 | 300 | 14.5 |
400 | 417.0 | 400 | 134.0 | 400 | 38.5 | 400 | 17.5 |
500 | 529.0 | 500 | 161.0 | 500 | 44.5 | 500 | 19.0 |
600 | 639.0 | 600 | 181.0 | 600 | 49.0 | 600 | 21.0 |
700 | 743.0 | 700 | 200.0 | 700 | 55.0 | 700 | 22.5 |
800 | 862.0 | 800 | 229.0 | 800 | 60.0 | 800 | 24.0 |
900 | 980.0 | 900 | 254.0 | 900 | 64.5 | 900 | 25.5 |
1000 | Not Shown | 1000 | 269.0 | 1000 | 67.0 | 1000 | 27.0 |
2000 | 2000 | 485.0 | 2000 | 109.0 | 2000 | 39.0 |
[ Return To Figure 5-27 ]
Alternative Text for Figure 5-28
Figure 5-28. Effective dynamic k value determination from d0 and AREA (AASHTO, 1993).
k = 50 pci | k = 100 pci | k = 150 pci | k = 200 pci | k = 250 pci | k = 300 pci | k = 500 pci | k = 1000 pci |
Deflection Basin AREA, inches | Maximum deflection, d sub 0, mils | Deflection Basin AREA, inches | Maximum deflection, d sub 0, mils | Deflection Basin AREA, inches | Maximum deflection, d sub 0, mils | Deflection Basin AREA, inches | Maximum deflection, d sub 0, mils | Deflection Basin AREA, inches | Maximum deflection, d sub 0, mils | Deflection Basin AREA, inches | Maximum deflection, d sub 0, mils | Deflection Basin AREA, inches | Maximum deflection, d sub 0, mils | Deflection Basin AREA, inches | Maximum deflection, d sub 0, mils |
NOTE: Corrected keff values are approximate and estimated based on the original figure included in the FHWA 05-037, May 2006, NHI Course No. 132040, Geotechnical Aspects of Pavements Reference Manual/Participant Workbook |
25 | | 25 | 25.5 | 25 | 17.1 | 25 | 12.6 | 25 | 10.2 | 25 | 8.5 | 25 | 5.1 | 25 | 2.5 |
26 | 26 | 21.8 | 26 | 14.7 | 26 | 11.0 | 26 | 8.8 | 26 | 7.4 | 26 | 4.4 | 26 | 2.2 |
27 | 27 | 18.6 | 27 | 12.4 | 27 | 9.3 | 27 | 7.5 | 27 | 6.2 | 27 | 3.8 | 27 | 1.8 |
28 | 28 | 15.5 | 28 | 10.3 | 28 | 7.7 | 28 | 6.2 | 28 | 5.3 | 28 | 3.2 | 28 | 1.5 |
29 | 24.6 | 29 | 12.6 | 29 | 8.4 | 29 | 6.3 | 29 | 5.1 | 29 | 4.2 | 29 | 2.6 | 29 | 1.3 |
30 | 19.8 | 30 | 9.9 | 30 | 6.6 | 30 | 5.0 | 30 | 4.0 | 30 | 3.4 | 30 | 2.0 | 30 | 1.0 |
31 | 15.3 | 31 | 7.6 | 31 | 5.2 | 31 | 3.8 | 31 | 3.1 | 31 | 2.5 | 31 | 1.6 | 31 | 0.8 |
32 | 11.2 | 32 | 5.5 | 32 | 3.6 | 32 | 2.8 | 32 | 2.3 | 32 | 1.8 | 32 | 1.2 | 32 | 0.6 |
33 | 7.7 | 33 | 3.8 | 33 | 2.6 | 33 | 1.9 | 33 | 1.6 | 33 | 1.4 | 33 | 0.8 | 33 | 0.5 |
34 | 4.7 | 34 | 2.4 | 34 | 1.7 | 34 | 1.2 | 34 | 1.0 | 34 | 0.8 | 34 | 0.4 | 34 | 0.3 |
35 | 2.2 | 35 | 1.0 | 35 | 0.8 | 35 | 0.4 | 35 | 0.4 | 35 | 0.4 | 35 | 0.2 | 35 | 0.1 |
36 | 0.0 | 36 | 0.0 | 36 | 0.0 | 36 | 0.0 | 36 | 0.0 | 36 | 0.0 | 36 | 0.0 | 36 | 0.0 |
[ Return To Figure 5-28 ]
Alternative Text for Figure 5-31
Figure 5-31. Correlation between coefficient of lateral earth pressure and overconsolidation ratio for clays of various plasticity indices (Carter and Bentley, 1991).
Plasticity Index = 10 | Plasticity Index = 20 | Plasticity Index = 30 | Plasticity Index = 60 | Boston Blue Clay, PI=23 (Ladd, 1965) |
Deflection Basin AREA, inches | Maximum deflection, d sub 0, mils | Deflection Basin AREA, inches | Maximum deflection, d sub 0, mils | Deflection Basin AREA, inches | Maximum deflection, d sub 0, mils | Deflection Basin AREA, inches | Maximum deflection, d sub 0, mils | Deflection Basin AREA, inches | Maximum deflection, d sub 0, mils |
NOTE: Corrected keff values are approximate and estimated based on the original figure included in the FHWA 05-037, May 2006, NHI Course No. 132040, Geotechnical Aspects of Pavements Reference Manual/Participant Workbook |
1 | 0.70 | 1 | 0.60 | 1 | 0.51 | 1 | 0.44 | 1 | 0.50 |
2 | 0.88 | 2 | 0.79 | 2 | 0.70 | 2 | 0.61 | 1.3 | 0.63 |
3 | 1.03 | 3 | 0.90 | 3 | 0.81 | 3 | 0.73 | 2 | 0.73 |
4 | 1.12 | 4 | 1.01 | 4 | 0.94 | 4 | 0.83 | 3 | 0.87 |
5 | 1.20 | 5 | 1.11 | 5 | 1.02 | 5 | 0.95 | 4 | 0.96 |
6 | 1.27 | 6 | 1.20 | 6 | 1.12 | 6 | 1.05 | 6 | 1.15 |
7 | 1.35 | 7 | 1.29 | 7 | 1.22 | 7 | 1.15 | 8 | 1.27 |
8 | 1.39 | 8 | 1.38 | 8 | 1.32 | 8 | 1.24 | 10 | 1.39 |
9 | 1.44 | 9 | 1.47 | 9 | 1.41 | 9 | 1.33 | 15 | 1.69 |
10 | 1.48 | 10 | 1.54 | 10 | 1.48 | 10 | 1.41 | |
20 | 1.81 | 20 | 2.12 | 20 | 2.26 | 20 | 2.10 |
30 | 2.01 | 30 | 2.48 | 30 | 2.71 | 30 | 2.60 |
[ Return To 5-31 ]
Alternative Text for Figure 5-33
Figure 5-33. Nomograph for estimating swell rate constant (AASHTO, 1993).
Moisture Supply = Low on Left Axis | Moisture Supply = Midpoint of Left Axis | Moisture Supply = High on Left Axis |
Road Bed Soil Fabric on Right Axis | Swell Rate Constant | Road Bed Soil Fabric on Right Axis | Swell Rate Constant | Road Bed Soil Fabric on Right Axis | Swell Rate Constant |
NOTE: The input for this graph is very subjective and will give only a very approximate estimate - Swell rate varies from 0.04 to 0.20. Right Axis is divided into 5 equal divisions for these tables where "Tight" = 0 and "Fractured" = 5. |
0 | 0.040 | 0 | 0.040 | 0 | 0.105 |
1 | 0.067 | 1 | 0.085 | 1 | 0.180 |
2 | 0.085 | 2 | 0.110 | 2 | 0.190 |
3 | 0.100 | 3 | 0.128 | 3 | 0.195 |
4 | 0.111 | 4 | 0.139 | 4 | 0.197 |
5 | 0.120 | 5 | 0.148 | 5 | 0.200 |
[ Return To Figure 5-33 ]
Alternative Text for Figure 7-9
Figure 7-9. Time Factor for 50% Drainage (ERES, 1999).
Slope Factor, (S1) Plotted on Log Scale | Time Factor, (T 50) Plotted on Log Scale |
0 | 0.700 |
1 | 0.217 |
2 | 0.140 |
3 | 0.118 |
4 | 0.095 |
5 | 0.830 |
6 | 0.074 |
7 | 0.069 |
[ Return To Figure 7-9 ]
Alternative Text for Figure 7-17
Figure 7-17. Guide to collapsible soil behavior (Rollings and Rollings, 1996).
Gs = 2.60 Saturation = 100% Curve | Gs = 2.70 Saturation = 100% Curve |
Liquid Limit % | Natural Dry Density lb/ft3 | Liquid Limit % | Natural Dry Density lb/ft3 |
For Any Value of Liquid Limit: Collapse is Likely for Natural Dry Densities Equal To or Less Than the Saturation = 100% Curve Natural Dry Density Value.
For Any Value of Liquid Limit: Swelling is Likely for Natural Dry Densities Greater Than the Saturation = 100% Curve Natural Dry Density Value
|
For Any Value of Liquid Limit: Collapse is Likely for Natural Dry Densities Equal To or Less Than the Saturation = 100% Curve Natural Dry Density Value.
For Any Value of Liquid Limit: Swelling is Likely for Natural Dry Densities Greater Than the Saturation = 100% Curve Natural Dry Density Value
|
13.5 | 120.0 | 15 | 120.0 |
20 | 106.5 | 20 | 109.0 |
30 | 91.0 | 30 | 93.0 |
40 | 79.5 | 40 | 81.0 |
50 | 70.0 | 50 | 71.5 |
60 | 63.0 | 60 | 64.0 |
70 | 57.0 | 70 | 58.0 |
80 | 52.0 | 80 | 53.0 |
85 | 50.0 | 87 | 50.0 |
[ Return To Figure 7-17 ]
Alternative Text for Figure 7-21
Figure 7-21a. Thickness design curves with geosynthetics for a) single wheel loads (after USFS, 1977, and FHWA NHI-95-038, 1998).
cNc | Required Aggregate Thickness inches (mm) |
5,000 lb | 10,000 lb | 15,000 lb | 20,000 lb | 25,000 lb | 30,000 lb | 35,000 lb |
psi | (kPa) | Full Size pickup truck | 2 yd3 Wheel Loader | 3 yd3 Wheel Loader | 4 yd3 Wheel Loader | 5 yd3 Scraper | 15 yd3 Scraper | 20 yd3 Scraper |
1 | ( 7 ) | 47.3 | ( 1201 ) | 66.5 | ( 1689 ) | |
1.5 | ( 10 ) | 39.0 | ( 991 ) | 54.2 | ( 1377 ) | 67.7 | ( 1720 ) | |
2 | ( 14 ) | 33.9 | ( 861 ) | 47.2 | ( 1199 ) | 58.5 | ( 1486 ) | 68.7 | ( 1745 ) | |
2.3 | ( 16 ) | | 70.0 | ( 1778 ) | |
3 | ( 21 ) | 27.8 | ( 706 ) | 38.5 | ( 978 ) | 47.5 | ( 1207 ) | 55.5 | ( 1410 ) | 61.0 | ( 1549 ) | 69.2 | ( 1758 ) | |
3.5 | ( 24 ) | | 70.0 | ( 1778 ) |
4 | ( 28 ) | 24.3 | ( 617 ) | 33.0 | ( 838 ) | 40.5 | ( 1029 ) | 47.3 | ( 1201 ) | 52.0 | ( 1321 ) | 56.1 | ( 1425 ) | 62.7 | ( 1593 ) |
5 | ( 34 ) | 21.3 | ( 541 ) | 29.5 | ( 749 ) | 36.2 | ( 919 ) | 42.2 | ( 1072 ) | 45.9 | ( 1166 ) | 51.0 | ( 1295 ) | 55.9 | ( 1420 ) |
6 | ( 41 ) | 18.9 | ( 480 ) | 27.0 | ( 686 ) | 32.8 | ( 833 ) | 38.0 | ( 965 ) | 41.7 | ( 1059 ) | 46.1 | ( 1171 ) | 50.6 | ( 1285 ) |
7 | ( 48 ) | 17.4 | ( 442 ) | 24.9 | ( 632 ) | 30.5 | ( 775 ) | 35.0 | ( 889 ) | 38.7 | ( 983 ) | 42.7 | ( 1085 ) | 47.0 | ( 1194 ) |
8 | ( 55 ) | 16.6 | ( 422 ) | 23.0 | ( 584 ) | 28.2 | ( 716 ) | 32.4 | ( 823 ) | 36.2 | ( 919 ) | 40.0 | ( 1016 ) | 44.0 | ( 1118 ) |
9 | ( 62 ) | 15.0 | ( 381 ) | 21.5 | ( 546 ) | 26.6 | ( 676 ) | 30.7 | ( 780 ) | 34.0 | ( 864 ) | 37.9 | ( 963 ) | 41.4 | ( 1052 ) |
10 | ( 69 ) | 13.9 | ( 353 ) | 20.5 | ( 521 ) | 25.2 | ( 640 ) | 29.0 | ( 737 ) | 32.2 | ( 818 ) | 36.0 | ( 914 ) | 39.4 | ( 1001 ) |
20 | ( 138 ) | 9.4 | ( 239 ) | 13.7 | ( 348 ) | 18.2 | ( 462 ) | 19.5 | ( 495 ) | 21.5 | ( 546 ) | 24.2 | ( 615 ) | 27.1 | ( 688 ) |
30 | ( 207 ) | 7.1 | ( 180 ) | 10.7 | ( 272 ) | 12.5 | ( 318 ) | 14.5 | ( 368 ) | 16.3 | ( 414 ) | 28.5 | ( 724 ) | 20.4 | ( 518 ) |
37 | ( 255 ) | 6.0 | ( 152 ) | |
40 | ( 276 ) | 6.0 | ( 152 ) | 8.2 | ( 208 ) | 9.9 | ( 251 ) | 11.1 | ( 282 ) | 12.8 | ( 325 ) | 14.6 | ( 371 ) | 16.1 | ( 409 ) |
50 | ( 345 ) | 6.0 | ( 152 ) | 6.1 | ( 154 ) | 7.8 | ( 198 ) | 8.6 | ( 218 ) | 9.8 | ( 249 ) | 10.8 | ( 274 ) | 11.9 | ( 302 ) |
51.5 | ( 355 ) | 6.0 | ( 152 ) | 6.0 | ( 152 ) | |
55.5 | ( 383 ) | 6.0 | ( 152 ) | 6.0 | ( 152 ) | 6.0 | ( 152 ) | |
60 | ( 414 ) | 6.0 | ( 152 ) | 6.0 | ( 152 ) | 6.0 | ( 152 ) | 6.3 | ( 160 ) | 7.0 | ( 178 ) | 7.3 | ( 185 ) | 8.1 | ( 206 ) |
61.7 | ( 425 ) | 6.0 | ( 152 ) | 6.0 | ( 152 ) | 6.0 | ( 152 ) | 6.0 | ( 152 ) | 6.0 | ( 152 ) | |
62.5 | ( 431 ) | 6.0 | ( 152 ) | 6.0 | ( 152 ) | 6.0 | ( 152 ) | 6.0 | ( 152 ) | 6.0 | ( 152 ) | 6.0 | ( 152 ) | 6.0 | ( 152 ) |
63 | ( 434 ) | 6.0 | ( 152 ) | 6.0 | ( 152 ) | 6.0 | ( 152 ) | 6.0 | ( 152 ) | 6.0 | ( 152 ) | 6.0 | ( 152 ) | 6.0 | ( 152 ) |
70 | ( 483 ) | 6.0 | ( 152 ) | 6.0 | ( 152 ) | 6.0 | ( 152 ) | 6.0 | ( 152 ) | 6.0 | ( 152 ) | 6.0 | ( 152 ) | 6.0 | ( 152 ) |
80 | ( 552 ) | 6.0 | ( 152 ) | 6.0 | ( 152 ) | 6.0 | ( 152 ) | 6.0 | ( 152 ) | 6.0 | ( 152 ) | 6.0 | ( 152 ) | 6.0 | ( 152 ) |
Figure 7-21b. Thickness design curves with geosynthetics for b) dual wheel loads (after USFS, 1977, and FHWA NHI-95-038, 1998).
cNc | Required Aggregate Thickness inches (mm) |
Tandem 8,000 lb | Tandem 11,000 lb | Dual Wheel, Single Axle 9,000 lb | Tandem 17,5000 lb |
psi | (kPa) | 10 yd3 Dump Truck | 14-16 yd3 Dump Truck | Highway Legal | Legal Log Truck |
1 | ( 7 ) | 52.7 | ( 1339 ) | 59.3 | ( 1506 ) | 65.8 | ( 1671 ) | |
1.2 | ( 8 ) | | 70.0 | ( 1778 ) |
1.5 | ( 10 ) | 40.7 | ( 1034 ) | 46.8 | ( 1189 ) | 52.3 | ( 1328 ) | 60.5 | ( 1537 ) |
2 | ( 14 ) | 34.0 | ( 864 ) | 39.7 | ( 1008 ) | 44.9 | ( 1140 ) | 52.0 | ( 1321 ) |
3 | ( 21 ) | 26.9 | ( 683 ) | 31.8 | ( 808 ) | 36.3 | ( 922 ) | 42.0 | ( 1067 ) |
4 | ( 28 ) | 22.5 | ( 572 ) | 26.9 | ( 683 ) | 31.4 | ( 798 ) | 35.4 | ( 899 ) |
5 | ( 34 ) | 20.3 | ( 516 ) | 23.8 | ( 605 ) | 28.0 | ( 711 ) | 31.4 | ( 798 ) |
6 | ( 41 ) | 18.2 | ( 462 ) | 21.5 | ( 546 ) | 25.6 | ( 650 ) | 28.4 | ( 721 ) |
7 | ( 48 ) | 16.6 | ( 422 ) | 29.4 | ( 747 ) | 23.4 | ( 594 ) | 25.5 | ( 648 ) |
8 | ( 55 ) | 15.5 | ( 394 ) | 17.8 | ( 452 ) | 21.7 | ( 551 ) | 23.5 | ( 597 ) |
9 | ( 62 ) | 14.4 | ( 366 ) | 16.5 | ( 419 ) | 20.3 | ( 516 ) | 21.9 | ( 556 ) |
10 | ( 69 ) | 13.4 | ( 340 ) | 15.5 | ( 394 ) | 18.9 | ( 480 ) | 20.5 | ( 521 ) |
20 | ( 138 ) | 7.6 | ( 193 ) | 8.6 | ( 218 ) | 11.5 | ( 292 ) | 11.8 | ( 300 ) |
25 | ( 172 ) | 6.0 | ( 152 ) | |
29.8 | ( 205 ) | 6.0 | ( 152 ) | 6.0 | ( 152 ) | |
30 | ( 207 ) | 6.0 | ( 152 ) | 6.0 | ( 152 ) | 7.6 | ( 193 ) | 8.0 | ( 203 ) |
36 | ( 248 ) | 6.0 | ( 152 ) | 6.0 | ( 152 ) | 6.0 | ( 152 ) | 6.0 | ( 152 ) |
40 | ( 276 ) | 6.0 | ( 152 ) | 6.0 | ( 152 ) | 6.0 | ( 152 ) | 6.0 | ( 152 ) |
50 | ( 345 ) | 6.0 | ( 152 ) | 6.0 | ( 152 ) | 6.0 | ( 152 ) | 6.0 | ( 152 ) |
60 | ( 414 ) | 6.0 | ( 152 ) | 6.0 | ( 152 ) | 6.0 | ( 152 ) | 6.0 | ( 152 ) |
63 | ( 434 ) | 6.0 | ( 152 ) | 6.0 | ( 152 ) | 6.0 | ( 152 ) | 6.0 | ( 152 ) |
70 | ( 483 ) | 6.0 | ( 152 ) | 6.0 | ( 152 ) | 6.0 | ( 152 ) | 6.0 | ( 152 ) |
80 | ( 552 ) | 6.0 | ( 152 ) | 6.0 | ( 152 ) | 6.0 | ( 152 ) | 6.0 | ( 152 ) |
[ Return To Figure 7-21 ]
Alternative Text for Figure C-1
Figure C-1. Chart for estimating structural layer coefficient of dense-graded asphalt concrete based on the elastic (resilient) modulus (AASHTO, 1993).
Elastic Modulus |
EAC, (psi) of Asphalt Concrete (at 68°F) | Structural Layer Coefficient, a1, for Asphalt Concrete Surface Course |
105,000 | 0.200 |
150,000 | 0.255 |
200,000 | 0.295 |
250,000 | 0.330 |
300,000 | 0.365 |
350,000 | 0.390 |
400,000 | 0.420 |
450,000 | 0.445 |
500,000 | 0.460 |
[ Return To Figure C-1 ]