Study On Dynamic Characteristics Of High Pier And Large-span Continuous Rigid Frame Bridge

In recent years, the construction of China’s high grade highway constantly develops inthe southwest and northwest regions. In order to adapt to a variety of special terrainconditions, such as deep groove, canyons, and great rivers, Long-span continuous rigid framebridge with high-rise piers has great spanning capacity, the characteristics of the pier-beamforce collaboratively and the elegant appearance, so these advantages make it the firstselection of bridge type in those areas. However, there are a lot of the frequent earthquakes inthe northwest and southwest regions and the transverse wind in the canyons. Theseunfavorable factors result in dynamic and stability problems of bridge structure. Therefore, itis necessary to study on the seismic analysis of long-span continuous rigid frame bridge withhigh-rise piers. Based on a Bridge as the background, this article analyzes the dynamiccharacteristics, stability and structure internal force and deformation under adverse loadsituation of this bridge.By research on the dynamic characteristics of this structure, this paper gets its30ordernatural vibration mode and the natural frequency of vibration, analyzes the model of thebridge under different natural frequencies, and obtains the dynamic characteristics of thebridge.The main pier of the Bridge is as high as104m, so it is indispensable to research onbridge structure buckling stability. Structural stability research of the Bridge includes theanalysis of the critical load coefficient in construction stage maximum cantilever state andoperation status. It gives the structure of the first4order buckling mode, gets the stablesecurity coefficient of the four states, and preliminarily concludes that the maximumcantilever state is the most unstable structure for the largest cantilever phase construction andbridge operation proposed.Secondly, the seismic response analysis of the bridge are analyzed with the responsespectrum analysis and time-history results. The response spectrum analysis and time-historyresults are compared and take the maximum used for seismic analysis.The calculatedmaximum value are used for seismic analysis, and validate the structural seismic design.Finally, the main pier of the Bridge which is as high as104m belongs to the high pier.The main pier do not design transverse beam, so that it is softer than others along the bridge, and is more likely to to happen the buckling instability in the construction stage and bridgephase, therefore, this paper studies the influence of the different pier type for long spancontinuous rigid frame bridge with high-rise piers.The paper proposes three types of the piers, such as the original main pier, the single pierand the pier with a cross beam. Through the study of the different type pier, it can provide areference for the design of long-span continuous rigid frame bridge with high-rise piers.