Differential settlement control threshold at road-bridge transition section based on ride comfort
To address the issues of excessive differential settlement and secondary derailment in traditional road and bridge transition section,a approach slab structure with a rigid-flexible continuous transition is proposed.This design combines the practices of road and bridge engineering by placing the approach slab at a certain depth and incorporating secondary sleeper beams,which are cast-in-place together with the ap-proach slab.The aim of this design is to improve the stress distribution and deformation of the bridge head subgrade.Quantitative indices were presented in order to study the differential settlement control threshold at road-bridge transition section of highways at different levels.Then,a two-dimensional five-degree-of-freedom vehicle vibration system analysis model was established in accordance with the relationship be-tween input excitation and output response of vehicle vibration systems based on analyzing the action mech-anism of bridge-head bumps.After that,calculation models were constructed in accordance with the treat-ments at the road-bridge transition section of highways of various levels.Differential settlement control threshold at road-bridge transition section of highways of various levels based on ride comfort was deter-mined with the root-mean-square value of human comfort weighted acceleration solved by a written pro-gram.The results indicate that the control threshold at the road-bridge transition section of the highway is a longitudinal slope variation value controlled from 0.30％to 0.40％.Specifically,first-grade,second-grade,and third-grade highways are ranged from 0.40％to 0.55％,from 0.50％to 0.75％,and from 0.95％to 1.35％,respectively.Besides,the control threshold at the road-bridge transition section of the fourth-grade highway is the step height that should be controlled within 0.05 m.
万方数据
维普
