Study On Earthquake-resistant Capability For Continuous T-Beam Bridge

In the various types of bridges, the beam bridge with simply supported beam and continuous beam bridge as representative is relatively simple, however the most common and also the most commonly used. So in the earthquake, in order to ensure the safety of lifeline engineering, and strengthen understanding for the earthquake behavior of the beam bridge and its significance is particularly important.By learning from predecessors in the research results of the continuous beam bridge's seismic performance, this paper further study several problems of the continuous beam bridge, main contents are as follows:1,According to the superstructure characteristics of multi-span continuous T-beam bridge with the double-column piers, the fine model, beam lattice model and single beam model are set up and have been comparatived and analysised, the impact of three different modeling ways to structural dynamic properties of different pier's height and the seismic response and seismic response of different venues conditions vibration input is investigated, study show that:the beam bridge model of 10m, 20m, 30m high piers at seismic input of different venues, the error of single-beam model calculation is small, the single-beam modeling is facilitate simple and modeling accuracy can meet project needs.2,Study the impact of the successor of bridge on three typical terrain conditions to the T-beam bridge vertical and horizontal seismic response . Study found: In longitudinal direction, if the structure of every span is similar and span's number of every joint is same or similar for the bridge on the plains terrain, anti-push stiffness of every joint is similar, collision effect of joints does not exist in the longitudinal direction, seismic response will not be passed between joints, so can only calculate single joint. For bridge on the canyon terrain or the slope terrain, because of the different anti-push stiffness , the structural characteristic periods is different and seismic response will be passed between joints, namely the adjoining structure have effect on seismic response, and the effect degree is different by different seismic motion input. In transverse direction, if the structure of every span is similar and span's number of every joint is same for the bridge on the plains terrain, anti-push stiffness of every joint is same ,because of the restraining action of the transverse stop block on the transition pier, collision effect of joints will exist in the transverse direction , and seismic response will be passed between joints , we can not only calculate the single joint, that is different with law of the longitudinal direction. In transverse direction, because of the different anti-push stiffness for the bridge on the canyon terrain or the slope terrain , the structural characteristic periods is different , and because of the restraining action of the transverse stop block on the transition pier, seismic response will be passed between joints, namely the adjoining structure have effect on seismic response, and the effect degree is different by different seismic motion input.3,discusses the impact of the different bearing form of multi-span continuous T-beam bridge to the longitudinal seismic response, as well as the impact of different constraint ways of multi-span continuous T-span beam bridge to seismic response in transverse direction. Study found: by adjusting the height of bearings can improve stiffness distribution of the continuous beam bridge, thereby improve the pier shear distribution, and reduce the clinical beam collision, it is effective adjusting the height of bearings on the improvement of such short-period seismic behavior of the bridge; Through deregulation transverse restraint of pier and beam can reduce the maximum moment of continuous beam bridge' s pier bottom in the transverse seismic loading; and it is different through changes transverse restrain of pier and beam on effect degree of the seismic response between the the plains bridge of consistent anti-push stiffness and the mountain bridge of inconsistent anti-push stiffness.