Determination of the Allowable Differential Settlement at the End of the Bridge without Approach Slab with Five-degree-of-freedom Vehicle Model

摘要

Relatively small differential settlement between the bridge abutment and the approach embankment causes the unsafe driving conditions and rider discomfort. This paper conducts a theoretical study on the determination of the allowable differential settlement. The longitudinal roughness in the bridge approach is much more serious than that in the general highway sections, then the pitch movement of vehicles can not be ignored, and the rider and seat were added to a half-track model to build a five degree of freedom vehicle model. The dynamic response analysis was carried out by the Laplace transform for the Man Vehicle Road system passing over the bridge approaches without approach-relative slopes. The results show that much difference will produce in the maximum transient vibration value of the acceleration and the vibration frequency when different vehicle models are used. So it is more reasonable to use the five degree of freedom vehicle model than the three degree of freedom vehicle model for the determination of the allowable differential settlement. In addition, the allowable differential settlement can be got by trial calculations after determining all the required parameters.