Identification method for pavement quality grade on basis of information of longitudinal section of road

The invention discloses an identification method for the pavement quality grade on the basis of information of the longitudinal section of a road. The identification method mainly comprises the following steps: (1) extracting effective information about elevation of the longitudinal section of a road and establishing a road database; (2) generating a power spectral density (PSD) curve in sections, and carrying out band-pass filtering processing; (3) extracting PSD pavement characteristic parameters, i.e., a pavement unevenness coefficient and a frequency index; (4) establishing a PSD pavement characteristic parameter database, and drawing a PSD characteristic parameter probability density distribution diagram; (5) converting the PSD characteristic parameters into IRI (International Roughness Index) values, generating a three-dimensional map and marking out road-quality-grade contour lines; and (6) quantitatively calculating the quality-grade distribution condition of the road. The identification method disclosed by the invention has the beneficial effect that with integration of the advantages of pavement evaluation methods such as a PSD method and an IRI method, and on the basis of the information about elevation of the longitudinal section of the road, the quality-grade distribution condition of the tested road is quantitatively identified.