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The earthquake is a part of the Earth's interior sharp movement transmit the vibration phenomenon, has always been a natural disaster of serious harm to human. The last 20 years, the global number of major earthquakes, especially in 2008, China's Wenchuan County, Sichuan 8 earthquake occurred, resulting in a large number of casualties and the destruction of buildings, bridges collapsed and roads damaged completely interrupted the epicentral area transportation, has brought great difficulties to the earthquake, highlights the importance of the transport system. Especially large-span cable-stayed bridge are generally transport hub project, investment, has a major impact on the national economy, and once destroyed in the earthquake, difficult to repair, and could easily lead to paralysis of the entire transport routes will resulting in huge direct and indirect economic losses. Therefore, correct and effective seismic design of the cable-stayed bridge, ensure the seismic safety has a very important significance. This article to Chengdu - Zigong - Luzhou projects - large bridge across the upper reaches of the Yangtze River the Yibin to Chongqing Blue Jiatuo reaches the engineering background, the use of professional bridge software MIDAS vibration characteristics and seismic response made a detailed analysis and discussion, summed up some meaningful conclusions and laws, to provide references for similar bridge seismic analysis, paper, completed the following aspects: (1) Refer to the earthquake at home and abroad, the cable-stayed bridge and seismic design of literature and its and summarized as the content of the introduction of this article; (2) Refer to the literature of the bridge seismic response analysis method, citing the main bridge seismic response analysis methods, including dynamic response spectrum method, dynamic time history analysis method and random vibration virtual excitation method. (3) a brief introduction engineering background and the basic theory of the finite element and its MIDAS software modeling, dynamic characteristics analysis. (4) According to the site safety assessment report to determine motion parameters input ground motion response spectrum analysis, dynamic response spectrum analysis, and compare modal combination method, damping ratio, vertical seismic and ground vibration input direction, for reference to draw some meaningful conclusions for the modeling and analysis of similar bridges. (5) According to the site safety assessment report to determine the vibration acceleration time histories input of ground motion time history response analysis, and analysis and comparison of pile and soil effects and side spans of the bridge approach, stiffness reduction, traveling wave effect, and finally compare response spectrum analysis and time history response analysis, draw some meaningful conclusions are available for reference to.
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