Experiment Research On Horizontal Mechanical Behavior Between Steel Anchor Girder And Cable-pylon

Anchorage zone on pylon, which are a critical part of the design of cable-stayedbridge, always withstand enormous tensile force from inclined cables. The anchoragezone on pylon of the Chishi big brige researched by this paper have two newcharacteristics：(1)The top/bottom plates have to dig holes to meet the need of tension space. Thechishi big bridge located in valley, which makes the part of pylon below decks arevery high. In order to keeping high tower’s stability, the vertical distance betweeninclined cables anchored on the anchorage zone on pylon will be designed shorter.This may cause tension space too little to tension inclined cables, in order to keepingconstruction process successfully finished, holes may need to dig on steel anchorgirder or steel box girder. However, holes themselves would increase both side’stensile stress along the longitude of bridge, even more, places around the holes wouldhave stress concentration phenomenon. Taking all this into consideration, it’sneccesery to carefully analyse the influence of holes to plate’s stress distributiondetailed.(2)The steel anchor girder-corbel composite structure used by the Chishi bigbridge are a new type of anchorage structure, becasuse of its reasonable anchoragemethod, it would used more and more in the future. But existing researchs onmechanic behavoir about this new type of anchorage method still incomprehensiveand need further research.This paper expanded reseachs on two ways. The one was how much the stressdistribution characteristics on plates are affected by holes, the other was thehorizontal mechanical behavior between steel anchor girder and cable-pylon.(1) Firstly, finite element model was established and combined with the full-scalesegment model test on pylon of the Chishi big brige’s anchorage zone, this paperdepthly analized the influene that holes affect the overall safety performance of steelanchor girder. Through finit element model, then found out stress distributioncharacteristics on plyon segment under different kind of load cases and instructed thesegment model test to carry out. The results showed that stress level of the wholeplates on steel anchor girder are relatively low, in other words, local holes digged intop/bottom plates don’t causing safety problems on steel anchor girder. (2)This paper proposed the universal theoretical expression to calculatehorizontal component distribution ratio of inclined cable force on the changes of steelanchor girder’s boundary condition for this new type of anchorage zone. Thecomparative analysis of experimental results, theoretical results and FEA resultsshowed that the error obtained by above three methods ranged within10%. The errorbetween the theoretical results and the simulate results was within5%. Resultsshowed that the theoretical expression has a good precision, and is easy to use.Experimental results showed that horizontal component ratio distributed by steelanchor girder was nearly70%, whatever its boundary condition changed.Based on the theoretical expression, finally analized how parametrics, such asfriction coefficient, inclined angle of bar to simulate chamfer, length of side wall,length of end wall and section area of anchor girde, to influced the horizontalmechanical bahavior of anchorage zone on pylon. According to results, eachparametric had evdient influcence on the distribution of horizontal force between steelanchor girder and cable-pylon, except for inclined angle of bar to simulate chamfer.