The Dynamic Characteirstics Analysis Of Asymmetric Conitnuous Rigid Frame Bridge

The bridge is regarded as an effective method when it strides across the rivers and deep valleys, it plays an important role in the realization of mountainous area of traffic engineering constructions. Bridge as a lifeline project, its destroy will increase the damage of secondary disasters when it subjects to strong earthquake, grasping and understanding of bridge’s dynamic characteristics under earthquake are meaningful for establishing of a more rational seismic system. Western region of China is full of mountains and complex terrain, the bridges are always designed to asymmetry structure systems; it needs to be arranged asymmetrically, so this kind of bridge is different from symmetry structure, such as structural stress, deformation of bridge, reinforcing bars, in construction and so on.Based on Rontgen Bridge which located in Yunnan province, this paper presents a relative comprehensive an in-depth study of the basic theory about asymmetry continuous rigid frame seismic performance, the main contents of this paper are as follows:1. Based on the actual engineering, with professional finite element software Midas/Civil, it’s to establish the asymmetry continuous rigid frame bridge finite element analysis calculation model with beam elements, and analyzed its vibration characteristics.2. To consider both the Longitudinal and vertical and horizontal and vertical seismic action, and solve the seismic response spectrum analysis of the structure force, due to the high and low Pier height varies, It’s here obtained the ultimate capacity of special section in6#and7#pier, and compare with each other, it’s aim is to view how much use of the material’s properties.3. Using time history analysis method to solve the internal forces of the structure under earthquake. Bridge model for this article is based on Rontgen Bridge in Yunnan province, it is using the El-Centro wave closing to natural period and peak acceleration with site, only to consider the earthquake action along the bridge and cross the bridge, and compared the calculation results of time-history analysis and response spectrum analysis, the final results showed that the result of response spectrum analysis is larger than time-history analysis, which proves the response spectrum analysis is reliable.4. Take Longteng Bridge in Yunnan Province as the background project, this paper briefly introduces the construction key points in the practical engineering of bridges. Including the ordinary bridge pier and bridge box beam construction method, the construction method of prestressed box beam, pier, pier cap and bridge deck pavement construction technology.5. Compute the stress of the girder in asymmetric continuous rigid frame bridge, to acquire the experience value of strand dosage, the paper analysis the prestressed steel beam dosage of the bridges which have been built. Then, through the calculation model of Longteng Bridge the paper analysis the dosage of the prestressed steel in different directions. The aim is to verify whether the experience value is reliable, and the result shows that the experience value is reliable.