Study On Train-bridge Vibration Induced By Viaduct Rail Traffic And Control

ABSTRUCT:With the rapid development of urban rail traffic, viaduct rail traffic, as one part of urban rail traffic, also develops quickly. The vibration and environmental problems induced by urban rail traffic have been attached more attention as well. When trains run on viaducts of south extension of Nanjing subway line one, abnormal vertical vibration comes along. Taking the phenomena as an engineering background, this paper studies the train-bridge vibration induced by viaduct rail traffic and control methods.This paper studies the vibration of train and bridge by means of theoretical analysis, numerical simulation analysis, experimental verification. In the recognition of natural vibration frequency of subway train, this paper deduces the dynamics equation considering the dynamic interaction of adjacent trains. In this paper, fastener stiffness is also considered in the analysis of train-track-bridge dynamic interaction. The main conclusions are as follows:(1) Actual parameters and natural vibration frequency of trains are obtained by field test of car-body natural vibration and adjustment of natural vibration frequency of trains, so the conclusion that the resonance between trains and bridge will not occur are drawn.(2) The velocity condition for resonance between trains and bridge is given by the comparison of car-body natural vibration frequency with the equivalent motivation applied on trains when trains run through equivalent spans of simply supported beams.(3) Vertical vibration of trains will get strong when trains run faster. As the rate of loading gets higher, the vibration of trains will reduce.(4) Differences of damping fasteners will have remarkable effects on train-bridge vibration. Although related research shows that type DTVII2fastener has worse effect on the control of environmental vibration comparing with type Ⅲ shock absorber, this paper finds that type DTVII2fastener can do better in the control of train-bridge vibration than type Ⅲ shock absorber.With the combining of theory and experiment, a comprehensive test of the vibrational state of trains is carried out during the period of train operation, and the correctness of the above conclusions can be verified.