Analysis On Vehicle-Bridge Interaction Of Unity Of Road And Railway Viaduct

The railway transportation has sharply developed all around the world since itsbeneficial advantage like the huge transportation ability, time-saving and low carbonpollution. In order to solve the traffic problem in our country, the railway projectshave been increasingly built among the big cities. The unity of the railway and roadurban viaduct is the new form of bridge structure in the rush buildings. This form ofbridge is capable of highly using the public transportation line to meet therequirement of low carbon pollution and time-saving. Contrary to the general rail-roaddual using bridge, the range of the bridge boards are not equal to each other. Thespatial torsion effect of the structure under the action of automobile loading is obvious,which may affect the train system; second, the bridges generally go through the citydowntown area, where there are a large number of residential buildings, officebuildings, people activities. The structure-born noise of the bridge under the dynamicloadings is another problem to promote the bridge. Structure-born noise analysis needto use the vibration of the bridge as the boundary conditions. Due to the limited time,this paper first analysis the bridge structure vibration under the train and vehiclemoving loadings, and research on structure-born noise part will be handled as thefollowing research work.In this case, this dissertation conduct researches on this form of urban viaduct.Firstly, the finite element model is been made according to the design drawing, usingthe ANSYS software. Then, the vehicle model, which has17degrees of freedom, isbeen conducted by improving the10degrees of freedom conducted by Wanming Zhai.The parameter of the vehicle calculation model is set by using the B type vehicle. Thecontact relationship assumes that the wheel and the contact point does the samemotion. The whole system is solved based on the separate iteration method, in whichthe bridge motion function is solved by the ANSYS and the vehicle motion function issolved by the procedure written by the author based on the FORTRAN language.Finally, using this calculation system conduct the research that whether the carmoving on the road viaduct influence the motion of the vehicle moving on the railwayviaduct under the former one. On the other hand, this dissertation also conduct theresearch about the impact of track irregularity on the motion of the vehicle. After all,some beneficial conclusion have been made:(1) The motion of cars moving on the upper road of the unity bridge have little impact on the motion of vehicles moving on the nether railway of the bridge. Therefore,the structure type and design of the bridge in this paper can be used as an exampleto design such a huge bridge. On the other hand, the structure of the viaduct of thetrack and the road can be designed separately;(2) To the vehicle-train-bridge couples system in this paper, the track irregularity canbe seriously affect the train subsystem, however, it has litter influences to thebridge structure since the displacement at mid-span changes little under differentspectrum of track irregularity. Therefore, the track irregularity can be ignored incoduncting the design of the train loadings to this bridge.(3) The track irregularity greater than the Third level track can meet the requirementof the serviceability of the vehicle vibration. Therefore, the operating companycan take this into consider in order to decrease cost of the project;(4) The criterion in GB5599-85of Sperling is more reasonable than the criterion ofmax acceleration during the evaluation system, the latter one is just a simplifiedmethod.