Safety Analysis Of Moving Vehicles On The High-pier And Large-span Continuous Rigid Frame Bridge Under Crosswind

With the rapid development of transportation,bridges build up in the canyon,sea wind environment.Strong winds will exacerbate the vibration of vehicles and bridge,lasting vibration will reduce the vehicle driving safety and comfort.Travel in the vehicles on the road,if the face is strong winds will lead to insufficient engine power;driving on the bridge vehicle,if by strong wind may cause the vehicle sideslip or rollover.In recent years,such as the wind and rain,ice,snow and other inclement weather conditions occur frequently,it is very important to study the safety of the vehicle on the bridge.Based on the research of coupling vibration of wind-vehicle-bridge system,the establishment of the vehicle sideslip and roll accident model under crosswind,dynamic response analysis of bridges and vehicles using the developed coupling vibration of wind-vehicle-bridge system program.Combined with the engineering example,the safety of bridge deck of high pier and long span continuous rigid frame bridge under crosswind is studied.This research work could be concluded as follows:1.Introducing the coupling vibration of wind-vehicle-bridge system analysis theory and establishing a three-dimensional model with 7 DOFs of the vehicle and the vehicle-bridge coupling vibration equation.The road roughness simulation into a zero mean smooth Gauss function.By the power spectral density function through the Fourier transforms simulation of the deck roughness sample.The coupling differential equation of the wind vehicle bridge system is established and solved by Newmark-? method.2.Simulation of fluctuating wind field in three dimensional space by using improved harmonic synthesis method,numerical simulation of wind load on vehicle and bridge.The finite element method is used to establish the model of high-pier and large-span continuous rigid frame bridge and the modal analysis is carried out for the model of the bridge.3.Wind loads on vehicles and bridges considering road roughness,a program for the analysis of coupling vibration of wind-vehicle-bridge system.Example of Shi Lianghe large bridge,the dynamic response and impact coefficient of the bridge span and the vehicle mass center of the vehicle under the wind load are analyzed by using the program.4.Introducing probability and statistics method,the establishment of the vehicles side-lurch accident and side slipping accident model by the probability of a statistical method.The vertical contact force of different pavement,different speed,different wind speed,different models,different High-pier bridge and different radius of curvature bridge is calculated by using the program,the effect of the calculation result on the safety of the bridge deck.The traffic critical wind speed of side-lurch in different speed and different wind speed side-slipping for the moving vehicles at four road conditions were calculated,respectively.Accordingly,this work can provide certain basis for the critical wind speed and speed of the vehicle across the bridge.