The Seismic Response Analysis Of Long-Span Continuous Rigid Frame Bridge During The Construction Process

In recent years, Seismic activity more frequently in southwest of China. The seismic response of long-span continuous rigid frame bridge which is during the construction has a great impact on the whole bridge. But In the existing condition of the construction process, long-span continuous rigid frame bridge’s construction cycle generally longer it makes the probability increases in the construction of long-span continuous rigid frame bridge. So there is necessary to analysis the seismic response analysis of construction process. As can be seen from the recently earthquake damage to the bridge. Since the pile-soil effects consideration is inadequate during the bridge construction process. It makes the bridges are generally more serious damage.When an earthquake occurs, domestic and international research to the seismic response of long-span continuous rigid frame bridge during the construction which is considering the pile-soil effects is less. Sichuan Red River Bridge is a example In this paper. Using response spectrum method and dynamic time-history method to analysis the most unfavorable conditions during the construction and the results were compared. The main contents are as follows:1、According to the development of seismic analysis’s theory, it summary a Series of seismic analysis’s theory. By way of transverse contrast and pointed out the advantages and disadvantages of various seismic response analysis theory, describle the adaption scope of each method. Discusses the main several factors that influence the seismic response during the construction, and prepare for the following article.2、Introducing some detailed analytical methods of long-span continuous rigid frame bridge dynamic and dynamics characteristics, combined these dynamics. Used finite element software MIDAS to Establish two kinds of Sichuan Red River Bridge model which are consider the pile-soil effect and not consider,and the results obtained from the vibration and dynamic characteristics after the completion of the full-bridge at various stages of construction, and get the result of the vibration and dynamic characteristics which is the whole bridge and during the construction.3、Using response spectrum method to analysis several unfavorable construction process about long-span continuous rigid frame bridge of seismic response analysis. The result of shows that two kinds of model shows that the displacement and frequency which is considering the pile-soil effects is increased with the construction of the bridge. According to different seismic excitation which is input different direction the bottom of pier’s moment and shear trend to increasing slowly.4、Using the time history analysis method to analysis the seismic response of the same construction process which is considering the pile-soil effects, compared the results of two kinds of model that excitate in the single direction. It can get the same conclusion that with the response spectrum method. But if the excitation input through both directions. The bottom of pier’s moment and shear trend to different variations, but the response of the structure has reached the maximum at this time, the seismic resistance of structures is got to the unfavorable state.