Seismic Response Analysis Of Skew Continuous Girder Bridge Under Earthquake Actions Considering The Duration

Skew bridge has a strong ability to adapt to the terrain for its structure meets the requirement of the line,and is used widely in modern bridge engineering.Compared with the orthogonal bridge,the structural stress analysis and seismic design of skew bridge is complex for its irregular shape.The existing domestic and foreign research about the seismic response of the skew bridge and its structural measures are still in the process of continuous exploration and improvement of engineering experience,so it is of great significance to analyze the seismic response of skew bridges.Duration which is one of three elements of earthquake is considered to have an important influence on the seismic damage of structures.Significant duration based on Arias strength is thought to have important significance and value of research.Calculating and analysising the response spectrum of different seismic durations on the basis of skew continuous girder bridge and PEER seismic record database and theoretical knowledge of response spectra.At the same time,based on the time history analysis of earthquake,the difference of ground motion responsed between 90%duration 70%duration and the total time and the change regularity of skew continuous girder bridge with slope and ground motion input angle is studied in this paper.Finally,the pounding effect of skew continuous girder bridge under earthquake is studied.The major studies and creative intents are as follows:(1).The summary of seismic damage of skew bridge and its research status are given in the front of this paper,also introduces the research and development of seismic duration.Then conclude the seismic design of the bridge and the seismic response analysis method and the failure criterion of the bridge structure and the determination of the damage index and summary of the calculation method of seismic durations in detail.(2).Introduce the calculation of the seismic response spectrum in detail.Select the earthquake records from the PEER seismic record database based on the skew continuous girder bridge.At the same time,divide seismic wave duration into 90%and 70%duration by the definition of significant duration,then calculate the acceleration response spectrum and dynamic magnification factor β spectra and compare with the result of the 100%duration,the result showed that:the response spectrum under three durations coincide with each other well.(3).Through the seismic time history analysis of skew continuous girder bridge by changing skew angle and input angle under different skew angles.Using the deformation index of bridge structure,based on the analysis of three kind durations of seismic waves,which reveals that for one-way input,the seismic response of the skew continuous bridge regularity and consistent numerical under three kinds of durations.Hoeever,for bidirectional input,the result of 90%and 70%duration are different with total duration in variation law and numerical value.(4)Divide the seismic records based on 90%duration,then the influence of seismic wave input angle,skew angle and clearance width of expansion joint on pounding effect is investigated when one-way input seismic wave is investigated.Similarly,the effect of the pounding on the pier and girder displacement is studied.