The Influence Research Of The Concrete Continuous Box Girder Bridge Dynamic Performance

Under the current technical conditions, the first simply supported aftercontinuous beam bridge has gradually replaced the traditional single beambridge add the deck continuous, which has become the most common structureform in highway and city roads Bridges in our country. Now in the design of thefirst simply supported after continuous system the concrete bridge, mainlycontains static design, there is not enough stress on the analysis of the bridgestructure dynamic performance, especially the structure calculation undervehicle load impact effect, consider impact coefficient of the bridge structure isconcerned with natural frequencies, not considering the influence on impactcoefficient of the multi-across number.while it is founded that there are certaindifference in actual test. It is founded that under the condition of the same line,equal the number of cars, long continuous span beam bridge occur diseasesmore often than short continuous span beam bridge in the detection of technicalconditions in highway Bridges. This paper regard the first simply supported aftercontinuous system concrete box grider bridge as the research object, from theperspective of the vehicle bridge interaction dynamic response, study theinfluence on structure dynamic performance and impact coefficient of themulti-span box grider Bridges in connecting quantity, order, drivingarrangement, pavement roughness and driving speed etc.The concrete research content is as follows: 1. Establish bridge beam finite element model by using ANSYS finiteelement software, in order to ensure the precision of beam model, do entitymodeling analysis of the bridge, and natural frequencies of the entity modelingis used to fix beam model, for ensure the accuracy of calculating vehicle bridgecoupling vibration analysis.2.Deduce a quarter and the half of vehicle model from the dalembert’sprinciple.3. According to the power spectral density function, simulated A, B, C, Dfour grades road by using the MATLAB software, and draw the curve ofsamples.4.Compile the calculation program of vehicle bridge vibration response,verify the correctness of the program by numerical examples.5. Regard connecting quantity and span for parameters, set up the car in themiddle road, a car partial load, two cars double lane, a train team centered onfour kinds of driving conditions, analysis variation law of connecting bridgedeflection and control section internal force under the vehicle bridge action, andget some conclusions.6. Analysis impact coefficient changing with the continuous across numberunder the influence of such as speed, road surface roughness, the arrangement ofdriving and get several conclusions.The results of this paper perfect the current concrete in bridge connectingthe bridge impact factor values, for the design of connecting concrete box girderbridge based on structural dynamic optimization, has significant engineeringapplication value.