For this exercise, you are to design a roadway that is to carry 100,000 people a day (excluding truck occupants) – 50,000 in design direction. The vehicles that carry these people include; (1) personal vehicles (average occupancy of 1.2 people per car) 2-2 kip single axles, and (2) buses with 2-22 kip single axles (assume they are filled with an average of 40 passengers). There are also trucks on the roadway and all trucks have 1-40 kip triple axle, 1-32 kip tandem axle, and 1-8 kip single axle. You know that the soil CBR is 6, the initial PSI is 4.5 and the TSI is 2.5. Other values to be used: All drainage coefficients = 1.0 Reliability = 90% Overall standard deviation of traffic = 0.50 Concrete Modulus of Elasticity = 5.5 million lb/in2 Concrete Modulus of Rupture = 750 lb/in2 PCC load transfer coefficient = 3.0 Design a rigid and flexible pavement, to last 15 years, for a four-lane road (four lanes in design direction) with 400 trucks per day in the design direction, and 20% of all travelers going by bus (the rest go in personal vehicles). Sketch cross-section of your two pavement designs and show all parameter assumptions. Do not forget to determine the amount of traffic that will be in the “design-lane” before beginning your computations (see Table 4.10). Procedure: Determine W18 for rigid and W18 for flexible (they will not be the same). Assume SN =4 and D =10 to get the axle-load equivalence factors. Determine design lane W18 for 4 lanes (design conservatively). See Table 4.10. For flexible pavement, select layer materials and thicknesses using Eq. 4.3
For this exercise, you are to design a roadway that is to carry 100,000 people a day (excluding
truck occupants) – 50,000 in design direction. The vehicles that carry these people include; (1)
personal vehicles (average occupancy of 1.2 people per car) 2-2 kip single axles, and (2) buses
with 2-22 kip single axles (assume they are filled with an average of 40 passengers). There are
also trucks on the roadway and all trucks have 1-40 kip triple axle, 1-32 kip tandem axle, and 1-8
kip single axle. You know that the soil CBR is 6, the initial PSI is 4.5 and the TSI is 2.5. Other
values to be used:
All drainage coefficients = 1.0
Reliability = 90%
Overall standard deviation of traffic = 0.50
Concrete Modulus of Elasticity = 5.5 million lb/in2
Concrete Modulus of Rupture = 750 lb/in2
PCC load transfer coefficient = 3.0
Design a rigid and flexible pavement, to last 15 years, for a four-lane road (four lanes in design
direction) with 400 trucks per day in the design direction, and 20% of all travelers going by bus
(the rest go in personal vehicles).
Sketch cross-section of your two pavement designs and show all parameter assumptions. Do not
forget to determine the amount of traffic that will be in the “design-lane” before beginning your
computations (see Table 4.10).
Procedure:
Determine W18 for rigid and W18 for flexible (they will not be the same). Assume SN =4
and D =10 to get the axle-load equivalence factors.
Determine design lane W18 for 4 lanes (design conservatively). See Table 4.10.
For flexible pavement, select layer materials and thicknesses using Eq. 4.3
1 1 2 2 2 3 3 3 SN a D a D M a DM
Trending now
This is a popular solution!
Step by step
Solved in 11 steps with 20 images
