Dynamic Response Analysis Of Cable-stayed Bridge

With the span of cable-stayed increasing, structure type diversification, lighter and other unique advantages, long-span cable-stayed bridge is one of the most popular modern bridge types. It is well known that the Cable-stayed bridges have become the hinge of transportation, once destroyed during the earthquake, it will bring heavily impact to the work of salvage and rehabilitation of disaster area and lead to huge economic loss. Therefore, it is necessary to study and master the earthquake response of long-span cable-stayed bridge. This paper took a comprehensive study of dynamic characteristics and the seismic response for Xigu Yellow River Large Bridge.Xigu Yellow River Large Bridge located Xigu area of Lanzhou and diagonally across the Yellow River. It is a twin towers and double cable planes, Semi- floating structural system and pre-stressed concrete cable-stayed bridge, which main span is 360 m and full- length is 1003 m, because of it typical system and complex structure,. So it is very important and meaningful study of dynamic characteristics and seismic response analysis for Xigu Yellow River Large Bridge.The main jobs which were studied as follows:1.On the basis of some references of the long-span cable-stayed bridges and at home and abroad, we can obtain parts of bridges is the weakest link by summarized and analyzed damage to bridges in recent years, the important of seismic analysis of long-span cable-stayed bridge is introduced and the advantages and disadvantages of these methods are analyzed.2.The space finite element dynamic calculation model of Xigu Yellow River Large Bridge is developed with the advanced analysis program Midas/C ivil and the dynamic properties are obtained through modal analysis. The results accord with the features of half- floating cable-stayed bridge.3.Based on the vibration characteristics of the Cable- Stayed Bridge, this paper choose the standard response spectrum is inputted form longitudinal, transverse, vertical and combination of direction(longitudinal+ vertical、transverse+ vertical and three-dimensional seismic input) respectively, which inputted spectrum analysis is done to estimate seismic response of this bridge.4.In order to take better account of some nonlinear effects of the bridge structure, considering. Therefore, the EI-CEN TRO earthquake wave(1940) is chosen to dynamic time-history analysis of the Xigu Yellow River Large Bridge. The response characteristics of the bridge are obtained in every single direction and Combination direction under seismic waves by dynamic time- history analysis method, and carries on the detailed analysis and summary.5. The results of two methods(response spectrum analysis and dynamic time- history analysis) were compared with each other, obtained seismic response displacement of dynamic time-history analysis significantly larger than the results of spectral analysis at the main parts of structure, therefore, the Xigu Yellow River Large Bridge seismic analysis to dynamic time-history analysis, supplemented by response spectrum analysis, The final result of seismic response is obtained.The research results in this paper pro vide some reference and suggestions for the seismic response analysis of seismic design structure system of the Xigu Yellow River Large Bridge, and some further research and solve problems are indicated.