Selections Of Ground Motions In Seismic History Analysis For Bridges With High Piers

Recently, more and more high-pier-span continuous rigid frame bridges, up to one hundred meters high above the pier, are built in the strong earthquakes areas of western China. China's new highway & bridge seismic design details (JTG/T B02-01-2008) provides:if the single-span is greater than 150 m or the height of pier is more than 30 m, the special seismic design of bridges should be a dynamic time-history analysis, and the results of time-history analysis and response spectrum method should be checked with each other. This paper take a long span and pier to hundreds meters high rigid frame bridge for example, with meeting requirements of statistical consistency of the standard response spectrum, This paper researches the selection of the seismic waves in time-history analysis. Major work and progress are as follows:(1) An overview of high-pier bridge construction and seismic problems is taken; a detailed summary about the earthquake damages and the repair of the hundreds meters high pier Bridge Miaoziping is particularly conducted for reference.(2) The earthquake records database for bridge seismic analysis is described, the statistical consistency issues of average earthquake response spectrum and the standard spectrum is analyzed, and the selection method of seismic record, considering the impact of high seismic vibration mode, in time-history analysis is raised.(3) Take a long span and pier to hundreds meters high rigid frame bridge for example, with the application of bridge software MIDAS/Civil, a finite element model is built and a vibration characteristic analysis is taken, and the calculation results were compared with others and the field measurement results, indicating that the value model is credible.(4) Response spectrum and time history analysis were taken for the long span and high pier rigid frame bridge, the pier's internal forces along to pier height distribution is the main consideration, the proposed election wave method's availability are initially validated. The necessity of seismic time-history analysis for high-pier bridge is emphasized.