Study On Transverse Seismic Capacity Of Simply Supported Viaduct In Urban Rail Transit

Urban rail transit has a large volume,fast and convenient,safe and reliable,and by other means of transport within the city small disturbance,along with the construction and development of our city,and its importance is more and more obvious advantages,will become the preferred way to solve the traffic congestion in large and medium-sized city in china.In urban rail transit,the cost of the elevated is low,operating energy consumption is small,and the proportion is becoming bigger especially in urban and suburban areas where the connection line is elevated line.But in the past earthquakes that the urban rail viaduct bridges were badly destroyed especially the transverse earthquake damage.However there are many shortages in the seismic research.So it is necessary to carry out meticulous research on the seismic capacity of the urban rail transit as it is the lifeline project.In this paper,it is mainly carries out the following aspects based on the urban rail viaduct simply-supported bridge.(1)On the basis of consulting a large number of relevant literatures,the paper analyzed the earthquake damage characteristics of urban rail viaduct bridges,reviewed the researches of the seismic capacity of piers and urban rail viaducts..(2)Based on the characteristics of urban rail viaducts in China,OpenSees software is used to establish the finite element model of urban rail Viaduct Bridge considering the orbital system.After extracting the transverse pier model and studying the effect of structural parameters on the lateral seismic piers.The results show that the increase of the span ratio reduces the lateral resistance and ductility of the structure,and the bridge pier ductility capacity is reduced with the increase of axial compression ratio.The increase ratio of the longitudinal reinforcement has a significant effect on the seismic capacity of the pier and also the increase ratio of the volume stirrup can improve the ductility capacity of bridge piers..(3)Through the quasi-static loading of the double-column piers with or without tie beams,the comparison of the energy dissipation between hysteretic curve and skeleton curve and the analysis of the protection ability of the tie beams to the bridge pier that using IDA methods.It is turned out that the tie beams can increase the pier's energy dissipation and achieves the purpose of controlling the damage of the bridge piers.(4)Using Pushover method from the angle of the whole bridge to carry out the research of the transverse seismic capacity of urban rail viaduct,the results show that the track structure plays an important role in improving the transverse seismic capacity of urban rail viaduct simply-supported bridge but with the increase of distance from roadbed locking point,the improving effect decreased.Through comparing the seismic capacity of the transverse pier model and the whole bridge,it is found that the seismic capacity of the single column pier model is less than the whole bridge while capacity curve of the double column pier fits better with the capacity of the whole bridge.(5)Combining Sozen damage model,the paper obtained the damage of the single and double column type of urban rail viaduct Bridges in ?field under different intensity of situations.