Test: Stresses in Flexible Pavements

The assumption by Boussinesq was the soil is homogeneous, elastic and isotropic under a circular load.

The two elastic theory was developed by Burnister after Boussinesq developed the equation for evaluation of stress.

Boussinesq assumed the load as a single point load acting at a depth z and radius r.

The depth is zero, so the stress represented is at the surface of the pavement.

 The depth is a function of the stress, depth and radius of the load acting on the point.

The radius is zero so it is possible only in a chart, which represents a point in the center of the chart.

The Poisson’s ratio for a homogeneous soil is assumed as 0.5.

The value of the constant F in finding out the deflection is 1.5.

 The deflection is measured in mm, cm or m depending on the requirement of the pavement.

The constant value of the pavement in rigid pavement design is assumed as 1.18.