Abstract:

In the light of the irregular tire contactshape and the non-uniformity of wheel pressure,  the mechanical response of semi-rigid pavement structure was studied by using the three-dimensional finite element method with three types of load distribution as uniform circular load, uniform rectangular load and non-uniform rectangular load. The results showed that both tire contact shape and non-uniformity of wheel pressure had significant impacts on the mechanical responseof semi-rigid pavement structure, particularly sensitive to the shear indexes underoverloading conditions. Uniform circular assumption and uniform rectangular assumption could not accurately reflect the shear indexes on the effect of overload, compared with a good response under the non-uniform rectangular assumption. Two suggestions where proposed to estimate the mechanical response of semi-rigid pavement structure. The conventional uniform circular load assumption can be used to analyze the mechanical response of pavement structure under the standard axle loadand the underload conditions. The non-uniform rectangular loadassumption should beused to analyze the mechanical response under overload conditions, considering the sensitivity of shear indexes.

Key words: load distribution; non-uniformity; mechanical response; road engineering