Trial-Design Research On420m Combination Arch Bridge With SRC-steel Web Members

Long-span concrete arch bridges are needed in the construction of mountainhighway and railway, however, its application is still restricted because of its greatweight and hard construction. So the main research ideas of concrete arch bridge withsuper long span turns to using steel-concrete composite section to lighten arch ringand optimize construction method.Firstly, in brief review of concrete arch bridges’ history, the node problem withapplication of steel web member-concrete composite section in long-span bridge ispointed out. And in combination with the common construction method of skeletonreinforced in long-span concrete arch bridge, this new-type composite section of SRC(Steel Reinforced Concrete)-steel web member is presented.Secondly, under the background of the420m long-span concrete arch bridge-Wanzhou Yangtze River Bridge, which adopts skeleton reinforced and is currently thelongest in the world, trial-design research on SRC-steel web member arch bridge isconducted and a finite element model established. Then, the feasibility of the newstructure is analyzed from three aspects (comparison of stress data in dead weight ofinitial model, selection of arch axis and of steel web member), and static properties incompletion state is compared with the original bridge and the waveform steel web(CSW)-concrete arch bridge. And the result shows this new-type bridge can reduceself-weight of main arch ring and axial force of arch ring, so it can be applied intosuper-long-span concrete arch bridge.And based on feasibility study tests, static analysis of trial-design arch ring inconstruction stage is carried out and compared with the original bridge. The resultshows that stress and construction time of both is similar in stage of erecting emptysteel skeleton, and in stage of injecting concrete in chord not only construction time isequal but the deflection and axial force of trial-design empty steel tube is close to theoriginal arch ring, while in stage of pouring outer-packed concrete they both havesimilar axial force and deformation (although self-weight of arch rings in castingconditions of trial-design is about30%smaller than the RC ones, its compressiverigidity is also about30%less than the RC’s) but the trial-design concrete-filled steel tubular takes time about30%less than the original.Finally, in order to analyze the seismic performance of the trial-design bridge,the time history analysis method is employed. It is shown that this new-type bridge’sarch ring is in smaller load reaction than the original concrete box arch andsteel-concrete composite arch on basic dynamic characteristics and seismic response,and so its shock resistance is superior to the original one.It is obvious that the application of SRC-steel web member combination archbridge into long-span concrete arch bridge has many advantages over the conventionalconcrete arch bridge and steel-concrete composite arch bridge. Therefore, it has thepotential to be introduced into the practical application.