How many types of methods are there to design a flexible pavement
There are three types of methods to design a flexible pavement they are empirical, semi empirical and theoretical method.
Empirical method is dependent on strength of
The strength of the soil sub grade is used to design the flexible pavement, because the sub base and base are more stronger than the sub grade, so design depends on sub grade only.
The stress strain approach is used in
The design of pavement using stress strain approach is used in semi empirical method, which depends both on theory and graph.
CBR is a
CBR is a method of designing the flexible pavement by using the soil characteristics.
The design charts are prepared based on
The design charts are prepared based on the past experience hence they are not reliable, as it changes according to location.
Axle load studies are carried out on a minimum sample of
The minimum sample size of axle load considered in India is 20%.
The heavy commercial vehicles are considered if their weight exceeds
The HCV are used to study the pavement design if their weight exceeds 3 tonnes.
The overlay design is laid for a maximum life span of
The maximum life span of an overlay design is 10 years, it may be also 5 years for small roads.
The most commonly used overlay is
The most commonly used overlay is flexible over flexible, rigid over flexible and rigid over rigid are also used but flexible is the most preferred and used pavement.
The average vehicles considered for pavement studies are
The commercial vehicles per day are considered as 150 to 1500 for pavement design studies.