Study On Lateral Vibration Performance Of Curved High Pier Bridges On Heavy Haul Railway

With the continuous progress of the expansion and reconstruction of freight railway,the existing railways in China are developing towards the direction of heavy load railway with large axle load,high traction and dense operation.At present,most heavy-duty railway lines are distributed in the central and western regions.In order to adapt to the high and steep slopes of mountains and the complex and changeable geological features,a large number of curved pier Bridges have been set up in the design of existing railway lines.Because the transverse bending line stiffness of the bridge with high piers is small,the transverse centrifugal force will be greater when the heavy load train passes the curved bridge,resulting in the increase of the transverse vibration response of the bridge with high piers with curves,which has a certain degree of influence on the normal passage of the heavy load train.Therefore,this thesis studies the transverse vibration performance of the curved high-pier bridge in service under the condition of heavy load train transportation by taking the curved high-pier bridge of heavy load railway as the research object,combining with theoretical analysis and operation performance test.The main research results are as follows:(1)The elastic-plastic dynamic finite element model of a typical bridge with high pier in service is established.Then,considering the load action of the crossing train with different running speed and axle weight,the vehicle-bridge coupling dynamic time-history analysis of the crossing train with heavy load is carried out,including the dynamic response laws such as transverse amplitude and transverse acceleration.The results show that the transverse amplitude of the bridge increases with the increase of the vehicle speed,but the correlation between the transverse amplitude and the velocity is small.With the increase of axle weight,the transverse amplitude of pier top increases more than that of mid-span.(2)Established different curve radius overloaded overload dynamic finite element model of railway curve of high pier bridge,analysis of all kinds of different axle load,speed and other factors on the curve radius of the influence law of high bridge pier transverse dynamic response,the different curve radius of high bridge pier transverse and lateral acceleration amplitude change characteristics and regularity of dynamic response.The results show that the transverse amplitude of curvilinear bridge with high pier is the smallest when it reaches the design speed of 80 km/h.The transverse amplitude and transverse acceleration of curved high pier bridge are positively correlated with the axial weight.The transverse amplitude and lateral acceleration of curved pier bridge are negatively correlated with the curve radius.(3)A typical curvilinear high-pier railway bridge in service was selected to carry out dynamic performance test and compared with the above theoretical analysis results to further verify the dynamic performance and response law of curvilinear high-pier railway bridge under the condition of heavy load transportation.The results show that the selected heavy-load railway bridge can satisfy the safety of heavy-load trains,and the test data verify the correctness and applicability of the calculation model.