Study On Dynamic Characteristics And Seismic Response Of Reinforced Concrete Arch Covered Bridge

Covered bridges is the combination of bridge and normal building structure, which has experienced more than two thousand years development course in our country.On the one hand, in the modern urban construction boom, because of its functional, beautiful and easy,can be given cultural meanings, and many other advantages, covered bridges engineering began to show a good momentum of development. On the other hand, the earthquake disaster is frequent in China in recent years, the seismic safety of construction has attracted more and more attention and recognition. There are few researches for the seismic safety, especially with the ordinary bridges under seismic action differences in mechanical behavior of covered bridges, which is a unique structure of the project, seismic design and seismic analysis are lack of available data and guidelines. Study on this aspect is important and urgent. Based on the above situations, study on dynamic characteristics and the seismic mechanical characteristics of a covered bridges in Shaanxi province was made in the thesis, the main research contents is as follows:First of all, this paper introduces the general situation and the development of covered bridges in our country, the seismic damage, bridges engineering seismic design specification and seismic analysis method, etc, these laid the theoretical foundation for subsequent research work.Secondly, based on a reinforced concrete arch landscape covered bridge, this thesis introduces the engineering outline of the project and the specific structure with the Midas/civil 2011 software to build multiple arch covered bridge structure finite element calculation models. Models include the bridge structure model(without frame building) and the whole covered bridges structure model(with frame building).Thirdly, according to the analysis of two different models for structural dynamic characteristics analysis of the characteristic value and modal vibration mode, their respective dynamic characteristics and the influence of the dynamic mechanical behavior from the upper building structure are studied.Fourthly, the response spectrum and time history seismic wave were acted on the structure respectively. Under the action of response spectrum, some control parameters are selected to study the difference of the two models. On the basis of an indicator of the bridge model under time history method, checking the value of analysis and calculation, the results show good results of two methods, which shows the calculation is accurate and reliable.Finally, the differences between this type of covered bridge structure and ordinary bridge structure in dynamic characteristics and seismic response are studied and analyzed, someconclusions of dynamic characteristics and seismic response about the covered bridges are obtained, which could be useful for seismic design and analysis of this type covered bridge.