Seismic Response Analysiis Of Multi-span High Pier Continous Beam Bridge In Construction Process

With the development of transportation in China,the construction of bridges is in full swing.In the construction of bridges,it is often necessary to cross the deep valley of the river.The continuous bridge with high piers is one of the commonly used bridge types at present.Due to the complex terrain across the ravine valley and the requirements for line alignment,bridge piers tend to be very high.The height and stiffness of each pier are very different.And the geological conditions are relatively complex.Therefore,the seismic response and the form of damage are not the same.All of these have brought some difficulties to the seismic design of the bridge.At present,the seismic design of bridges is mainly aimed at the design of the forming state of the bridge.There is no provision for the seismic code in the process of bridge construction.When the bridge is in the construction stage,its stability is poor and its stiffness is small,and a complete anti-seismic system is not formed.If there is an earthquake,its seismic response will be significantly different from the seismic response in the formed bridge state.Therefore,it is necessary to carry out relevant research on the earthquake resistance during the construction stage.This paper based on No.1 bridge of Ding Jiazhuang,and the seismic response analysis of the construction process of high pier continuous girder bridge is carried out.The main contents are as follows:(1)Select the typical pier,and a three-dimensional finite element model is established.The free vibration analysis and time history analysis were carried out in the state of bare piers.(2)The three-dimensional finite element model is established by taking the simple support state of the bridge as the research object.Then the free vibration analysis and time history analysis of bridge were carried out.The time history analysis gives the internal force of the bridge,the time history response of the pier top and the time history response of the key parts of the main beam.(3)Taking the formed bridge as a research object,a three-dimensional finite element model was established.Then the free vibration analysis and time history analysis of bridge were carried out.The time history analysis gives the internal force of the bridge,the time history response of the pier top and the time history response of the key parts of the main beam.The seismic response of the bridge in the construction process is compared and analyzed.In this paper,taking the project of No.1 bridge of Ding Jiazhuang as an example,the corresponding analysis of bridge seismic resistance are carried out during the entire construction process.