B):- Design a three layer flexible pavement system using the CBR method, knowing that the present AADT is (4200 v/d) the heavy vehicles represent 0.03 of it. The highway lifetime and the construction period about 15 years and the growth rate is (r=0.02). The CBR values are as follows: Subgrade soil = 8%, sub-base 15%, Base 80%. Make use %3D of the attached CBR curve

B):- Design a three layer flexible pavement system using the CBR method, knowing that the present AADT is (4200 v/d) the heavy vehicles represent 0.03 of it. The highway lifetime and the construction period about 15 years and the growth rate is (r=0.02). The CBR values are as follows: Subgrade soil = 8%, sub-base 15%, Base 80%. Make use %3D of the attached CBR curve

Traffic and Highway Engineering

5th Edition

ISBN:9781305156241

Author:Garber, Nicholas J.

Publisher:Garber, Nicholas J.

Chapter20: Design Of Rigid Pavements

Section: Chapter Questions

Problem 17P

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07. Determine Structural Number and terminal serviceability index value of flexible pavement. Given B and G, value for 32-kip tandem-axle loads. B= 0,4 G= -0.22
The traffic on the design lane of a proposed four-lane rural interstate highway consists of 25% trucks. If classification studies have shown that the truck factor can be taken as 0.45, design a suitable flexible pavement using the 1993 AASHTO procedure if the AADT on the design lane during the first year of operation is 1885, pi = 4.2. Growth rate = 6.5% %3D SN, Design life = 20 yrs Reliability level = 95% Standard deviation = 0.45 Surface course DI %3D SN2 %3D D2 %3D SN3 Base course Subbase course D3 Roadbed course The pavement structure will be exposed to moisture levels approaching saturation 20% of the time, and it will take about one week for drainage of water. Effective CBR of the subgrade material is 7. CBR of the base and subbase courses are 70 and 22, respectively, and Mr for the asphalt mixture, 3102 MPa (450,000 lb/in?).
Q6: Designing a Rigid Pavement Using the AASHTO Method (Find D) Effective modulus of subgrade reaction, k = 480 lb/in³ Mean concrete modulus of rupture, Sc = 725 lb/in² Load transfer coefficient, J = 3.9 Ec = 4500000 Drainage coefficient, Ca = 1.0 Design serviceability loss, APSI = 1.5 ZR (Standard normal deviation) = -1.282 Overall standard deviation, So = 0.4 Cumulative 18 kip ESAL = (37900000)
B. A rigid pavement with a 10-inch slab thickness, 90 percent reliability, E. = 4 million Ib/in?, 600 lb/in? modulus of rupture, 150 lb/in³ modulus of subgrade reaction, a 2.8 load transfer coefficient, initial PSI of 4.8, final PSI of 2.5, overall standard deviation of 0.35, and a drainage coefficient of 0.8 is designed. The pavement's design life is 20 years. The three-lane road is built for vehicles with one 20,000-pound single axle, one 26,000-pound tandem axle, and one 34,000-pound triple axle. Calculate the projected daily truck traffic on the three lanes
B. A rigid pavement with a 10-inch slab thickness, 90 percent reliability, E. = 4 million lb/in², 600 lb/in² modulus of rupture, 150 lb/in³ modulus of subgrade reaction, a 2.8 load transfer coefficient, initial PSI of 4.8, final PSI of 2.5, overall standard deviation of 0.35, and a drainage coefficient of 0.8 is designed. The pavement's design life is 20 years. The three-lane road is built for vehicles with one 20,000-pound single axle, one 26,000-pound tandem axle, and one 34,000-pound triple axle. Calculate the projected daily truck traffic on the three lanes.
Design a flexible pavement (Two way-Two lane) for a subgrade CBR value of 3.5,the number of daily traffic as shown in the table below, the reliability value is 90%, the standard deviation 0.35, the initial serviceability 4.5, terminal serviceability 2.20 and effect of weather swelling only. Assuming a 20-year design life and growth rate 2%. Assume that 80% of the ESALs in one direction.. (E2-30,000 psi, E3-11,000 psi, m. m, 1.08). Sketch cross section in your design. All axles should be taken in ESAL calculations. (Take IMPa =145.0 psi) Vehicle Class Passenger Car Single-unit truck Single-unit truck Semi-trailer Light truck Large semi-trailer Axles Weights 2 single axles, 2000 lb/axle 1 single axle, 8000 lb/axle 1 single axle, 14,000 lb/axle I single axle, 7000 lb/axle 1 tandem axle, 20,000 lb/axle I tredom axle, 28,000 lb/ axle 1 single axle, 12,000 lb/axle 2 tandem axles, 22,000 lb/axle 2 single axles, 3000 lb/axle 1 single axle, 12,000 lb/axle 2 tandem axles, 28,000 lb/axle Number…
2. You are asked to design a new flexible pavement structure for an existing road that will be totally replaced. You are provided with the following borehole results: a) Existing (Old) HMA - 135 mm b) Existing (Old) Granular A Base - 170 mm c) Existing (Old) Granular B Subbase - 340 mm d) Gravelly Silty Sand (Till) Subgrade (25 % 5-75 um) What is the current GBE for the existing pavement structure? What is the GBE for the same pavement structure when it was newly constructed?
A flexible pavement is designed to last 10 years to withstand truck traffic that consists only of trucks with two 18-kip single axles. The pavement is designed for a soil CBR of 10, an initial PSI of 5.0, a TSI of 2.5, an overall standard deviation of 0.40 and a reliability of 90%, and the structural number was determined to be 6. Determine the number of daily trucks traveling in the peak direction.
12. Refer to Figure II-1 attached. A flexible pavement is to be evaluated according to the AASHTO 1972 design guide. The existing pavement has a weighted structural number=3.4, a regional factor=2.0, and a soil support value=4.5. What would be the approximated number of daily equivalent 18-kip axles to be allowed on this road for a 20-year analysis period?a. 10b. 33c. 100d. 1490
Q: Evaluate whether 9in of slab thickness for rigid pavement will be adequate on a rural expressway for 20-year analysis period if design criteria are as follows: Pi = 4.5 Pt =2.5 ESAL over design period = 6* 10 Concrete Elastic modulus, Ee = 5*106 Ib/in? %3D Mean Concrete modulus of Rupture 700 Ib/in? Drainage Coefficient Ca = 1.0 R = 0.95 So = 0.3 K = 170 Ib/in %3D Load transfer coefficient = 3.2
Problem 1: A flexible pavement section is designed using a CBR of 20 for the subgrade. During construction it is found that the subgrade is softer with a CBR of 7. The contractor proposes to place a layer of select fill on top of the subgrade to compensate for this condition. How thick should the select fill layer be if the original pavement section is 8 inches HMA over 12 inches crushed aggregate base over subgrade. Assume a resilient modulus of 15,000 psi for the select fill and clearly describe the design method used to solve this problem as well as any assumptions and results PROBLEM 2: Design a rigid pavement that will last as long as the flexible structure from problem 1
Q2: The traffic on the design lane of a proposed four-lane rural interstate highway consists of 40% trucks. If classification studies have shown that the truck factor can be taken as 0.45, design a suitable flexible pavement using the 1993 AASHTO procedure if the AADT on the design lane during the first year of operation is 1150, pi = 4.5, and pt = 2.5 . Growth rate = 3% Design life = 20 years Reliability level = 95% Standard deviation = 0.45 The pavement structure will be exposed to moisture levels approaching saturation 20% of the time, and it will take about one week for drainage of water. Effective CBR of the subgrade material is 7. CBR of the base and subbase are 70 and 22, respectively, and Mr for the asphalt mixture, 3102 MPa (450,000 lb/in2).