The Study Of The Design Plan On New Fenglingdu Bridge Across Over The Yellow River And Approach Lines Connecting With Tongpu Railway

Old Fenglingdu bridge was built in 1966, it's across over the yellow river and connects with TongPu railway ..During employed long time, there happened many diseases on the bridge now. it has seriously threatened the safety of travelling crane. so the limited velocity of 20km/h has been claimed for the train passing through the bridge, it made the bridge almost cannot match the development of railway transportation and become a bottleneck of TongPu railway. It's obviously that only by mending of the bridge can not totally solve the problem, so a new bridge must be built instead of the old one as soon as possible. To build a new bridge will deals with the location of bridge ,the main span, the bridge form and the correclative lines tendency. Based on the study to the special geographical condition around location of Fenglingdu bridge and compare with several possible plans in details, the final location, span, bridge form and correclative lines tendency.are recommended in the thesis.The new《Code of seismic design of railway engineering》has been promulgated a few years ago, more strong rules has been brought forward to evaluate the antiseismic ability of a railway bridge. .As the new bridge is located on the area of VIII degree seismic fortification intensity and the main span crossing the main stream of yellow river is asked to be longer than 100 meters,. It's made the design of the new bridge more difficult. Based on plentiful data home and abroad, the main span was analysed by performing several statics and kinetic finite element programmes. According to the results, the author commend a totally new long-span structure of ascendant seismic,namely,consecutive box girder rigid frame bridge with hollow abdomen. Compared to the common box girder frame bridge, the new structure appears more excellent.(1) By adopting common prestressed concrete box sections to sustain more strong shearing forces at the pivot sections and ends sections and adopting hollow abdomen box girder to suit weaker shearing forces in central sections, it not only can fully exhibit the advantage of every kinds of girder, but also can light the weight of the girder to decrease the iner force during construction period and to makie the distribution of iner force more reasonable.(2) As the load of the abdomen beam will be greatly decreased, it made the earthquake respondence of the structure to be more weak and the rigidity of infrastructure to be controlled more easliy. So that, the antiseismic capability of the structure will be greatly improved.(3) Because of the lighter cantilever, the structure will be constructed more easily and the model is more early to control than common box girders.(4) The concrete and other material is obviously less than the common box girder, therefore ,the engineering cost is also lower evidently than common one.The hollow abdomen box girder is one of structure with deep potential at aspects of inner stress control, investment control and landscape. It's not only supplying one kind of new structure, but also opened the designer's idea.