Research On Seismic Response Characteristics Of Curved Girder Bridges

The seismic response of the highway curved bridge is difference from other bridges for the coupling interaction between the moment and torsion resulted from its irregular space structure. At present, both in China and abroad, the seismic design code of bridge has given some design guidance for curved bridges but have not given the specific method for anti-seismic design or rapid evaluation. The study of the character of the seismic response and performance of curved bridge need to be improved with a great quantity curved bridge engineering have been constructed. In this paper, a finite element model is built up for the study of the seismic response and performance of curved bridge by taking an example of a curved beam bridge engineering in Indonesia. In the study,20seismic models are set from3curve styles,3radius of curvature and2arrangements of bearings so as to overall analysis of curve bridge. The study scope covers nearly all curve bridges style of highway, which develops from4parts below:1. Achievements on curved bridge from domestic and overseas are reviewed and summarized. In Chapter One, it is introduced of the most unfavorable angle of earthquake input and extended its calculation formula to provide the theory basis for further study of next stage.2. The natural vibration properties of curved bridge are analyzed and proposed the "Modal Angle" as criterion to differentiate irregular structure vibration mode properties parameters. Base on calculation formula of the most unfavorable angle of earthquake input, compare the results of curve bridge when input the most unfavorable angle to verify the accuracy of simplicity calculation.3. The results of time-history dynamic analysis are compared with response spectrum method in curve bridge seismic response. Refer to the principle of choosing seismic wave,15seismic history records are chose for time-history dynamic analysis. Simultaneously, the mean values of these records are contrast with the value of transformational response spectrum. Then, the value of transformational response spectrum is contrasted with the value of specification design response spectrum. It is verified of there is a very small percentage error in these values. That is to say, for curved bridge, not only it can gain the precision conclusion, but simplify the calculation, which substitute time-history dynamic analysis by transformational response spectrum.4. The static elastic-plastic analysis method of curved bridge is discussed. For the reason of irregular of curve bridge, it is open to discuss if it is reasonable that conventional lateral loading pattern, detecting position to use analysis the curve bridge. In the study, it gains correct methods to solve the curve bridge static elastic-plastic analysis basing on its characteristic under different lateral loading pattern and detecting position.