Effect Of Heavy-haul Train Vibration On Bridges And Research Of Vibration Reduction

With continuous development of the national economy,the axle load and traction quality of heavy-haul train increase subsequently,which not only increase the burden of heavy railway infrastructure,but also cause the impact on the bridge along the railway line.China's heavy-haul train transportation mainly passes through the rural areas,the vibration response of the bridge along the line and the influence of the train running stability cannot be ignored.At present,the study on the vibration problem of heavy-haul trains,which is with heavy load and long duration,is relatively deficiently.Therefore,it is necessary to carry out the dynamic response analysis and vibration control of bridges along the heavy-haul trains.In this paper,the dynamic characteristics of the bridge vibration and the vibration reduction measures are studied based on the background of Shuohuang heavy-haul railway line.This project belongs to the National Natural Science Foundation of “study on the impact assessment and vibration of structures along the railway line”(project number: 51378500).The research contents and results are as follows:(1)On the basis of the design data of the heavy-haul railway bridge,the ANSYS model of single-span simply supported girder bridge is established.And the calculation theory of the deflection influence line of the simply supported beam under moving load is presented.(2)Based on the Bernoulli-Euler beam theory,the vibration analysis theory of simply supported beam bridge is presented.The motion equation of vehicle-bridge coupling vibration of simply supported beam bridge under the load of heavy-haul train is derived,the coefficient of fluctuating load is calculated,and the identification method of load excitation is obtained.Commit MATLAB programming and use the Newmark-?method of numerical simulation,to get the mid-span response of simply supported beam bridge.The analysis result shows that the maximum mid-span deflection of the bridge is beyond the limit specified in the basic code for design of railway bridges and culverts(TB 10002.1-2005).(3)Through the comparison and analysis of the maximum mid-span deflection of the bridge under different mass ratio and damping ratio,the mass ratio and damping ratio of the TMD system are determined.And different operating conditions are used to analyze the vibration control effect of TMD system.(4)Through the comparative analysis of bridge vibration response under different conditions before and after the vibration reduction shows that the tuned mass damper(TMD)system has a good damping effect on vertical vibration of simply supported girder bridge,and the installation of three TMD systems has better control effect than single TMD installation.The damping effect can meet the requirements of the bridge specification,and provide reference for the vibration reduction of the bridge along the heavy-haul line.