Mechanical Characteristics of Asphalt Pavement on Bridge Deck under the Braking Force of BRT Buses

To reveal the mechanical response characteristics of deck pavement under dynamic loads, taking for example the asphalt pavement of one viaduct in Chengdu, several asphalt pavement structures under the braking force of BRT buses were compared and analyzed by using the numerical simulation analysis methods and numerical analysis of orthogonal test. The selected pavement structure was taken as the further object, and the effects of moving vehicle speeds on the mechanical response of deck pavement on the braking deceleration section near the BRT bus stop were analyzed and its mechanism was also explained. The analysis shows that the vibration impact and loading period lead to the occurrence of critical speeds in surface vertical deflection and shear stress responses of the pavement. At different initial bus velocities, there is a short but fast-changing interaction of both positive and negative bending and shear stresses at each tire footprint area on pavement. in the surface layer. Under the braking loads, surface shear stresses were rather great, which arrived at a peak at an initial vehicle speed of 60 km/h. Near the bus stations where bus deceleration or acceleration occur frequently, anti-shearing and anti-fatigue performance of pavement structure should be improved and interlaminar bonding should be strengthened.