Fractal Parameters of the Grade of Road Surface Roughness

The eight-grade road surface data were simulated by inverse Fourier transform,according to road surface roughness grade standard.Its fractal parameters were calculated and the fractal parameter for the grade of road surface roughness was proposed.The result shows that the simulating roads display obvious similarity.Its fractal dimension was approximately 1.60,which had little difference of grade.The road surface roughness index unified the traditional statistical parameter and the fractal dimension,which was more suitable for the grade of the road surface.The road surface roughness index increases with the power spectral density.In other words,the lower the road surface roughness index is,the worse the road surface grade becomes.