Evaluation Method Of Driving Safety And Comfort Under Vehicle-Bridge Coupled Vibration For Large Span Bridge With High Piers

With the development of transportation,millions of bridges are built.High pier and large span prestressed concrete bridges are becoming more and more widely used.Meanwhile,the amount of vehicles running on highway bridges also increases,therefore,more attentions are paid on vehicle-bridge coupled vibration problems.Evaluation systems of train driving safety and comfort on railway bridges have been established systematically,however,similar researches on highway high pier and large span bridges under vehicle-bridge coupled vibration are relatively rare.As part of ministry of communications western project "analysis and research of vehicle-bridge coupled vibration and its influence" subproject "analysis about influence of vehicle-bridge coupled vibration on driving safety and comfort",this paper based on a continuous beam,a rigid frame bridge and a composite structure of the rigid frame and continuous beam in Shaanxi province,using numerical calculation methods to simulate multiple working conditions,carried out researches on evaluation methods of driving safety and comfort under vehicle-bridge coupled vibration.This paper taking different speeds and pavement grade into account,through large amounts of numerical calculations,obtained the envelope diagram of nodding acceleration and lateral-rotation angle acceleration; with the help of one third octave method and Fourier transform,processing the vertical acceleration time-history curve of vehicles running on the bridges and get the acceleration root-mean-square curve,then compared the curve with the fatigue-lowering efficiency curve which is formulated by ISO 2631 International Standard,take advantage of results to evaluate driving comfort when vehicles running on the bridge.Evaluation methods proposed by this paper can be used as references when evaluating driving safety and comfort under vehicle-bridge coupled vibration on such bridges.