The Evaluation Of Widening Concrete Continuous Girder Bridge's Seismic Performance

With the rapid development of the national economy, a substantial increase in the volume of traffic and transport, so that on completion of the highway end of the century the volume of traffic to adapt to life shortened significantly. To this end, it is necessary to widen the highway or the construction of double-track the transformation to resolve this contradiction. Transformation of the widening of the highway, which is an important part of the bridge to widen, and widen the bridge after the direct effects of broadening of the seismic performance of bridge structures. Therefore, to enhance the seismic performance of bridges as the target, analysis of the way which to widen the bridge has important theoretical and practical engineering value.In this paper, a continuous bridge between Shanxi Province background for the project. Research on the pier cross-section under the weight of the cross-section characteristics, taking into account the impact of the expansion joints and the pile - soil - structure effect, the use of large-scale finite element program to establish the background of the project ansys old bridge model and two different ways (The old and the new cover cap beam connection and beam separation of old and new)to broaden the bridge model full-bridge for dynamic analysis carried out on the basis of the equivalent plastic hinge method to widen the bridge after the elastic-plastic seismic response analysis and evaluation. Bridge to the longitudinal study, two kinds of cross-bridge to the condition of bridge structures to respond to the seismic analysis and discussion of the conditions of the formation of plastic hinge structure, development and failure mode analysis of the structure of each of the next earthquake occur plastic hinge location, time sequence, and form number. By studying the structure of the various conditions to the bridge in the longitudinal and cross-bridge can bear the greatest level of seismic loading, the realization of two bridges on the way to broaden the comparative analysis of seismic performance. Study shows that the conditions in the longitudinal bridge the widening based on the project in two ways, both of 0.4g peak acceleration under the El Centro seismic wave, the beam connecting the old and the new covered bridge widening, its pier in the destruction of time later than the beam separation of old and new bridges built, and the extent of the destruction of the former to the latter light. To the conditions in the cross-bridge, which is able to bear the largest peak acceleration of 0.3g of the El Centro seismic waves, but the beam to connect the old and the new covered bridge widening on the pier in time later than the destruction of the old and the new covered bridge beam separation, the destruction of the former the degree of light on the latter. The results show that Broaden the way the two bridges are the bridge to meet seismic requirements of the old;the use of the old and the new bridge cap beam built to connect the reinforcement beams of the bridge seismic transformation of the way performance is better than the separation between the two methods of transformation.In this paper, the results for a similar transformation of the reference bridge reinforcement.