Seismic Analysis And Seismic Isolation Of High Pier Prestressed Continuous Rigid Frame Bridge

As the rapid development of society,the corresponding also led to the rapid construction of the bridge.Continuous rigid frame bridge because of its ability to cross and the construction of convenient,more and more favored by the mountain area.Continuous bridge bridge and main span with the development of the need to constantly refresh the existing records,and specifically for the continuous rigid frame bridge seismic design is lagging behind the practical application of the bridge for seismic analysis,dynamic characteristics analysis,The study of beam parameters of thin-walled piers is of particular significance,and also provides some scientific basis for the seismic performance and safety of the bridge.The main contents of this paper are as follows:1 The dynamic characteristics of the bridge,the periodicity,the frequency and the vibration mode of the bridge are studied by using MIDAS / CIVIL professional software.2 The seismic response of the bridge is analyzed,and the four kinds of seismic load conditions are selected according to the standard of China,America and Europe.The contribution of the three directions to the internal force of the bridge is studied,and the most unfavorable seismic force method.The linear time history analysis of the structure is carried out,and the results of the comparison response spectrum and the time history analysis are compared to find out how to choose the appropriate seismic method in the seismic design.3 The establishment of a root beam,beam,two beams of a total of three models,discusses the vibration period of the three models,spectral method on structure under different load seismic response was analyzed by reaction,internal force and displacement of key interface to view results of three models of difference of influence degree of the earthquake in response,the overall creation of tie beam can increase the stiffness of the whole structure,reduce the concentration of stress,increasing the pier bottom seismic response influence but not the more the better beam.4 The length of the double leg thin-walled beam is made up of six models were studied according to the variation of displacement of bridge pier,pier cycle,internal force and internal force of the main beam,the reasonable range of double leg thin-walled beam is 3.5m-5m.5 Set the lead-core rubber isolation bearing at both ends of the bridge,and use the time-history analysis method.By comparing the internal force of the piers before and after the damping,it is possible to know that after installing the isolation device,The beam of the main beam is not much positive effect,but the bridge cross bridge to the shear force has a very significant reduction in the effect of the pier piercing significantly.These results can provide some reference for the design of the seismic isolation.