The Dynamic Characteristics And Anti-seismic Analysis Of Large Span And High-speed Rail Arc Bridges

The concrete-filled steel tubular arc bridges with tie bars, since they have themerits such as high bear capacity, long span, good anti-seismic performance,convenience of construction, aesthetic structure and so on, have been widespread usedin the practical engineering projects. However, the dynamic characteristics andanti-seismic analysis of concrete tube arc bridges have not been explored sufficientlycompared with other kinds of bridges. Recent years, the high-frequent earthquakes tookplace in our country always caused bridge destructions that disrupted the traffic anddelayed the disaster relief which could exacerbate the damage severely. Hence, it is veryimperative to conduct research to have a good command of the dynamic features ofconcrete tube arc bridges and provide scientific basis for bridge anti-seismic design andanalysis. In this thesis, the long-span concrete-filled steel tubular arc bridge on thehigh-speed rail line from Hefei-Fuzhou is established by commercial finite elementprogram Midas/Civil to analyze its dynamic response under the simulated earthquake.The main content of the research is shown as follows:1. Introducing the development and features of concrete-filled steel tubular arcbridge, characteristica of tied arch bridge, seismic analysis of bridgestructure,earthquake damage type of bridge and status of steel concrete bridgeseismic.2. Introducing the basic concept of structural seismic dynamics,target of seismicstructure,ductility seismic design of bridge and based on the performance of thebasic theory of seismic design of bridge.3. Introducing the overview of the bridge project,finite element model,analysis ofthe static and dynamic charecteristics of the bridge and vibration characteristicsin the vibration modes.4. Introducing the development, theoretical basis and applicable condition ofresponse-spectrum method specifically, then conducting seismicresponse-spectrum analysis of the arc bridge, obtaining the interior force anddisplacement of the main arc rib, piers, as well as tied beam, under theearthquake response. The influence of high-speed train load is computedthrough the comparison of two situations: with train and without train.5. Introducing the development, theoretical basis and applicable condition ofdynamic time-history method. then conducting seismic response-spectrum analysis of the arc bridge, obtaining the interior force and displacement of themain arc rib, piers, as well as tied beam, under the earthquake response. Theinfluence of high-speed train load is computed through the comparison of twosituations: with train and without train.6. Comparing the results of two methods applied in this thesis: response-spectrumand dynamic time-history to get the precision for the bridge.7. Summarizing the above content, the limitation and future work are presented.