The Research On Vibration Characteristic And Reduction Measures Of High Speed Railway Box Beam

In recent years, with the rapid development in high-speed railway construction in our country and higher demands for the train running speed and track regularity, which leads bridge structure, especially box beam occupied a large proportion in high-speed railway construction. With the change of the bridge structure and speeding up for the train, the vibration problem caused by box beam under the train loads attracked more and more people’s attention. Based on the 32 m box beam as the research object which widely used in the construction of high-speed railway, the finite element model was established by ANSYS, and the vibration characteristics of box beam which in different chamber structure or setting the stiffener in different position under high speed train load were studied.Chief works are summarized as follows:1. The first four natural vibration frequeney of box beam and the correspondent vibration mode were determined. And the rationality of the model was verified by compared with the measured data.2. The transformation rule of horizontal displacement, horizontal acceleration and longitudinal displacement, longitudinal acceleration of high-speed railway box beam under high speed train load were studied, the vertical displacement and vertical acceleration of box beam were determined as the main vibrating reference quantity3. The vibration performance of roof, floor, web and stems axillary in section of box beam which under high speed train load were studied.4. The vibration performance of box beam under different train wheel loads was studied. The transformation rule of vertical displacement and vertical acceleration of high-speed railway box beam under train load with time changing were determined.5. The longitudinal displacement of box beam under train load which showed a increasing trend from the end of box beam to the mid-span section, and from the center line of beam section to flange. The longitudinal acceleration in floor were even smaller than roof, and showed a increasing trend from the center line of beam section to flange.The end section of box beam under large impact effect with the train loads move in and out, the acceleration in flange, stems axillary position were higher than the same position in other sections.6. Te structure of double room in a single box for box beam or setting stiffening rib in the box beam had impact on the structure vibration. In the same train load, it is obvious that the vertical displacement and acceleration were decreased if setting longitudinal stiffener in the floor of box beam or using double room in a single box. The vertical displacement and vertical acceleration of the structure can be reduced to a certain extent when setting longitudinal stiffener in the web, but the decreasing amplitude is limited, the effect of vibration reducing is unconspicuous. Setting lateral stiffener in the floor, roof or web of box beam, the structural vibration are all can be not significantly reduced by these measures, which are not recommended as the structural design measures for vibrate reduction. Situation for setting longitudinal stiffener in the roof, the vertical displacement and acceleration for box beam were increased at a certain extent under train load, it is illustrated that the measure will increase the structural vibration,which should be avoided in structural design.In the end, on the basis of summing up the research achievements of the w hole, the questions which need to be further studied have been proposed.