Analysis of Asphalt Pavement Early Distress at Bus Stop Based on Vibration Acceleration Signal

Asphalt pavement distress at the bus stop is one of the major distresses of urban roads in populated areas - intensive metropolitan zones. In order to analyze the cause of this kind of road distress in Beijing City, the vibration loads caused by buses are studied. Firstly, the vibration acceleration of the asphalt pavement at the bus stop was measured on the field. Secondly, the vibration signal at three states, such as the state before buses coming to the stop (defined as N1 state), the state when buses are idle at the stop (defined as N2 state) and the state when buses start to leave the stop (defined as N3 state). These were modeled by a power spectrum analysis scheme separately. Thirdly, quantitative comparisons were made among the three kinds of dynamic signals measured at the above three states. Finally, a tentative conclusion is deduced, that is, one of the key factors which cause asphalt pavement early distress should be the dynamic load which is produced by bus performance characteristics at the time of starting to leave the stop. This specific dynamic load frequency lies between the 50~60HZ band.