Unbound Granular Materials

Tension is positive

Nonlinear anisotropic elastic (NAE) UGB model lead to a high horizontal tensile stress at the top area of base layer.

This stress distribution does not make sense as Unbound granular base (UGB) cannot sustain high tensile stresses

Nonlinear anisotropic elastoplastic (NAEP) model leads to compression on the top and little tension at the bottom of the base layer

This stress distribution makes sense

Nonlineary of UGB by stress-dependent resilient modulus at base layer which increases with an increasing load

The resilient modulus decrease with depth and with the distance from the loading centre