Design of flexible pavements - road pavements, Civil Engineering

Design of Flexible Pavements:

The design of flexible pavements is done by the CBR method. The CBR test, described further, gives an indication of the supporting power of the sub-grade soil. The other input needed for design is the traffic. Heavy commercial vehicles (trucks and buses) alone matter, and not the light vehicles like cars, two-wheelers and vans. Since the heavy commercial vehicles carry different loads, some heavy and some low, it is the practice to convert the axle loads to a standard axle load of 81.6 kN (8.16 T) by using the following formula :

Damaging power of an axle of weight W (in kN) = (W/81.6)4

Thus, if an axle load of a vehicle is 100 kN, its damaging power is :

(100 /81.6)4 = 2.26

This means that an overloaded vehicle with axle load of 100 kN causes damage to a pavement which is 2.26 times that caused by a standard axle load of 81.6 kN. If the damaging power of each vehicle is thus found and added up, and then divided by the number of commercial vehicles, one gets the Vehicle Damaging Factor (VDF).

VDF = Sum of damaging power of axles counted in a period/Number of commercial vehicles counted in the same period

Flexible pavements are designed for a life of 15 years. During the period, the traffic grows. A growth rate of 7.5 per cent per annum can be taken as a rough guide.

The distribution of traffic across a carriageway is needed for arriving at the traffic.

Posted Date: 1/22/2013 4:32:06 AM | Location : United States

Related Discussions:- Design of flexible pavements - road pavements, Assignment Help, Ask Question on Design of flexible pavements - road pavements, Get Answer, Expert's Help, Design of flexible pavements - road pavements Discussions

Write discussion on Design of flexible pavements - road pavements
Your posts are moderated
Related Questions
what type of ethics is environmentel ethics

1. What take place when float or slack of an activity is positive Ans: It represents a situation where extra resources are available and the completion of the project is not de

After measuring the anticipated traffic for the bridge, cement/reinforced- with- rebar stanchions are spaced over the freeway to accommodate the bridge. An 'off-ramp' from the free

A clay layer 24 metres thick has a saturated unit weight of 18 kN/m 3 . Ground water level occurs at a depth of 4 metres. It is proposed to construct a reinforced concrete foundati

A 30 cm diameter pile penetrates a deposit of soft clay 9 m deep and rests on sand. Compute the skin friction resistance. The clay has unit cohesion of 0.6 kg/cm 2 . Suppose

Water quality analysis: This water quality analysis presents an overview of physical characteristics of water, chemical substances that are normally present in water and vario

some expansion joint(10 mm- 20 mm) on my basement roof.rain water leakage in basement i want the solution of expiation joint and water leakes.

hi contactme 9902142308

The sketch shows a common consumer product called Water Pik. This device uses a motor to drive a piston pump that produces a jet of water (diameter d = 3 mm, temperature T = 10 °C)