Influence Of Vehicle Operation State On Fatigue Damage Of Prestressed Concrete Simple Girder Bridge

In recent years,with the volume of traffic rigid demand sharp growth,the statues of vehicle running demonstrate high present of excessive speed and overload,the volume of traffic haven became more and more huge,which lead to the fatigue life of the bridge rapid reduced due to the local field of existing bridge under the high frequency of heavily stress. In conclusion,it is very important to study how statues of vehicle running influence the prestressed simple girder bridge’s fatigue behavior. This article depend on both of theory of the finite element and traffic statistics to carry out the following research work:(1) The prestressed concrete structure’s fatigue damage theory and fatigue damage Analysis method was summed up in this paper.(2) As the research object of vehicle model,first of all,using Mechanics method to calculate the axle load in condition of vehicle’s different overload percentage. Second, contrasting types of 2 axle to 6 axle’s vehicle which in different overloading percentage influence the prestressed simple girder bridge’s fatigue behavior. Last not the least, researching the types of vehicle’s overloading percentage and fatigue damage of simple girder bridge’s mathematical relationship.(3) Using the tool of finite element software to analysis how the parameters which consist of vehicle speed, vehicle distance, continuous traffic and span of bridge influence the simple girder bridge’s fatigue behavior. Linear fatigue cumulative damage formula which consider of number of vehicles cross the bridge at the same time is proposed. Research showed that: vehicle speed affect the bridge impact coefficient and then indirect influence the fatigue life of the bridge. With the vehicle speed increase the fatigue damage of bridge reach to peak,while,it would be decrease if the speed continue growing. The larger number of the continues traffic the smaller of the fatigue damage. Impact on the fatigue damage of bridge spans besides itself characteristic value of cross section design, it’s relate to the axle distribution.(4) Based on the WIM, the volume of traffic data about Yilu high road was invested, and got the information about all tryps of vehicle’s percentage,vehicle speed,dynamic state of the volume traffic, vehicle’s weight and axle weight. The weight of vehicle and axle’s probability distribution model was described by GMM, then carried out the 6 fatigue load model vehicles. Estimating the fatigue life of existing bridge.On the basis of load model vehicle.