Analysis And Strengthening Method Of Curved Box Girder Bridge With High Piers After Earthquake

PC curved box girder bridges with nice torsion resistance has been widely applied inhighway bridge construction in china. Compared with the straight bridge, for the influence ofcurvature, PC curved box girder bridges has obvious bending torsional coupling effect.Therefore, the structural disease of lateral deviation of girder is easy to occur if theunreasonable bearings are adopted in PC curved box girder bridges.Based on a PC continuous curved box girder bridge, this paper analysed the causes ofstructural diseases, such as pier offset, bearing damages, and lateral deviation of girder.Furthermore, some strengthening methods were also put forward in order to improve thebearing capacity of it. The main jobs are as follows.Firstly, detailed investigations were carried out to learn characteristics of structuraldiseases, which was the basis of the damage analysis of structure. Secondly, using the methodof structural analysis, some action effects such as dead load, prestressing, temperature,earthquake were studied to analyse the influences about structural internal force, constraintreaction of bearings with different parameters as mentioned above. Structural analysis wouldprovide necessary references to help us learn the damage causes of bridge. Thirdly, accordingto the results of disease detection and structure analysis, the damage causes were analysed,which were focused on three aspects:(1) Earthquake influence;(2) Combined effects ofinternal force cumulation;(3) Weak limiting device design of bearing. In the end,strengthening principles, maintenance methods, key technologies and monitoring methodswere introduced in the paper. Construction examples showed that the strengthening methodshad lots of advantages of low cost, short construction period and advanced technology, whichcould be applied to the same kinds of bridge evaluation and strengthening.