How to Estimate the Stiffness of the Multi-Layer Road Based on Properties of Layers: Symmetry-Based Explanation for Odemark's Equation

When we design a road, we would like to check that the current design provides the pavement with sufficient stiffness to withstand traffic loads and climatic conditions. For this purpose, we need to estimate the stiffness of the road based on stiffness and thickness of its different layers. There exists a semi-empirical formula for this estimation. In this paper, we show that this formula can be explained by natural scale-invariance requirements.