Study on Calculation of IRI Based on Power Spectral Density of Pavement Surface Roughness

A new mathematical method of International Roughness Index is proposed,which is based on Power Spectral Density of pavement surface roughness.The quarter-car model is established to analyze the inputs of pavement surface roughness and the outputs of auto vibration.The power spectral density of pavement surface roughness is got by theoretic analyzing of dynamic response models.Applying the method of random vibration theory and so on,IRI which based on PSD of pavement surface roughness is deducted.Using PSD for IRI calculating can make vehicle industries and highway transportation agencies to compare their criteria and improve their production designs,and highway transportation agencies can make appropriate decision for pavement maintain accordingly.