Surface wave technique for measuring the elastic properties and thickness of roads: Theoretical development

The theoretical development of the experimental technique for measuring the elastic properties of the layers which make up a road is described. A knowledge of these properties is required in the development of a fundamental method of pavement design. The elastic properties are deduced from measurements of the wavelength and velocity of vibrations of known frequency along the surface of the road, and this paper develops the theory of the method of analysis of the relation between velocity and wavelength for single- and two-layer pavements.