The Dynamic Response On Vehicle Excited By The Vertical Profile Irregularity Of High-Pier And Long-Span Continual Rigid Frame Bridge Under Temperature

With the fast development of high-speed railway and the special line for passenger transport, the demand on the smooth-going of the line is more and more strict, then, a large number of viaducts and long-span bridges emerge as condition requires, among which continual rigid frame bridge become popular with numerous bridge designers with its favorable smooth-going of the line, good holistic performance of structures, good anti-seismic performance,convenience in construction and good economic benefits etc.Due to the characteristic of the high pier (the height is often more than 100 meters), the high-pier and long-span continual rigid frame bridge is affected greatly by climate factors, such as the difference in temperature during day and night and the radiation of the sunshine, meanwhile, the contraction of pier body makes large vertical profile irregularities of bridge deck and affects the irregularity of track structure. So far, the research on this special irregularity is few, and it is still open that if the irregularity will influence the comfort and safety of vehicles and the track structure in high-speed railway. Therefore, it is important and meaningful to make some corresponding research.The thesis takes a certain high-pier and long-span continuous rigid frame bridge (the span layout is 92m+168m+92m, the middle pier height is 112m) as an example, to make a series of computations and researches. According to the structure characteristic of the bridge, a space model is built with the large generally used finite element software ANSYS, and the temperature rise of the whole pier and beam was considered to calculate and analysis the vertical profile irregularities of the girder in the case of 10℃,15℃,20℃,25℃, respectively. On the basis of track irregularities calculation, the thesis takes CRTSⅡslab track used widely in the special line for passenger transport as the track structure of the bridge, and builds the train-track coupling dynamics model with the large generally used finite element software ABAQUS. Then, the dynamic response of the train-track coupling model is calculated in two cases, involving independent action of vertical profile irregularity caused by temperature rise of the bridge and the joint action together with the track random vertical profile irregularity. By analysis of some criterions influencing the comfort and safety of the vehicle, such as the vertical acceleration, the rate of wheel load reduction, and so on, we find that the vertical profile irregularities caused by the temperature rise of the bridge is of big amplitude, but due to the long wavelength, the rate is small, so it has little effect on the running train; in the joint excitation of the vertical profile irregularity caused by the bridge and randomness, with the speed increase, the vertical acceleration, the rate of wheel load reduction increase greatly, but the requirement of comfort and safety of the vehicle can also be satisfied.