Study Of Seismic Responses Of Continuous Rigid Frame Birdge With Large-span And High-pier Under Construction

In western part of China, rapid development of transportation has brought largemounts of local bridge constructions. Among most of these constructions, continuousrigid frame bridge becomes the best choice in terms of design due to its outstandingperformance. High-pier and large-span are remarkable characteristics of continuousrigid frame bridge. The reason to adopt these characteristics is result of the geographicfeatures such as high-mountain and deep-wide-valley in western part of China. Therecent earthquake records in China indicate that western part of China is anearthquake-prone area. At the same time, the prolonged construction period increasethe possibility of earthquakes occurrence during construction. However, what makes iteven worse is that high-pier and long-cantilever weaken the anti-seismic performanceof continuous rigid frame bridge. Unfortunately, there are few engineers have been inresearch of the earthquake responses of continuous rigid frame bridge underconstruction. Because of above mentioned reason, the main purpose of this paper is tothe study of the anti-seismic performance of continuous rigid frame bridge withhigh-pier and long-span by calculating the static response and seismic response of acontinuous rigid frame bridge named Youfanggou on the Provincial Highway No.307in different cases, and comprehensive analysis of these vast response results. The maincontents of this paper are as followings:1. We simplify the actual structure of the bridge by analyzing the mechanicalcharacteristics, loads, boundary conditions of the continuous rigid frame bridge. Then,we establish some typical models of different cases in preparation for subsequentcalculations;2. We calculate eigenvalue of different models and extract the first15vibrationmodes of the continuous rigid frame bridge to analyse the variation of self-vibrationcharacteristics on construction progress;3. Based on the first150vibration modes, we use response spectrum method tocalculate each model. After that, we compare results between respective models toobtain the variation of internal force, stress and displacement of critical section onconstruction progress under design response spectrum;4. After using time history method to calculate each model, we compare resultsbetween respective models to obtain the variation of internal force, stress, displacement and acceleration of critical section on construction progress under3different seismic waves;5. Based on comprehensive analysis of the results of response spectrum andseismic time history, we obtain the variation of bridge seismic responses onconstruction process. Then, we find out the critical case and critical structure ofcontinuous rigid frame bridge during earthquake.Conclusion of this paper can hopefully be a reference manual for future seismiccalculation of design and construction of similar continuous rigid frame bridge inwhich high-pier and long-span are involved. It may also be a reference for future coderevision.