Analysis And Experimental Study On Shear Performance Of PC Box Girder With Corrugated Steel Webs

The prestressed concrete (PC) composite box-girder bridge with corrugated steel webshas many advangtages,such as light self-weight,specific mechanical behavior,high effectivepretressing system,short construction period,beautiful shape etc.It has been extensivelystudied and applied abroad.We begin to study it very late,with efforts of reserchers,someresults have been achieved in bending performance, shear performance, torsionalperformance, dynamic performance and Long-term performance etc,which have beingguiding practice.At present,this structure has a booming trend in practice.Previous studies on the shear behavior of the corrugated steel webs are moreconcentrated in shear buckling,such as shear buckling form, failure modes, factors, theshear buckling strength calculations etc,so some shear behavior of the corrugated steel websneeds further research,such as shear sharing ratio among top and bottom concrete slabs,corrugated steel webs.Meanwhile,the calculation method of web shear stress increasedunder partial load need be studied well.Therefore,this artcle is based on the projectsupported by Natural Science Fund,“Study on long term performance of composite boxgirder with corrugated steel webs”.then carrying out static loading test that includes the PCcomposite box girder with corrugated steel webs,the RPC composite box girder withcorrugated steel webs and the concrete girder, and combining with finite element analysistheory,studying on the shear stress distributing and shear sharing ratio of corrugated steelwebs.Meanwhile,the related performances of the actual bridges are calculated and analyzed.It can be concluded that:1) The experimental results is consistent with the results offinite element analysis well, The shear is evenly distributed along the height direction ofweb,but it is unevenly distributed along the longitudinal direction,which is influenced bysome factors: prestressed steel, the thickness of the top and bottom concrete boards,diaphragms, the thickness of web etc.There is a proportional relationship between shearstress of straight segment and ramp segment’s in adjacement the straight segment,the ratiosis cosine of twists dip both straight and ramp segments.2) The corrugated steel webs sharea large proportion of shear in section,the ratios are nearly79%~83%,whether the test boxgirder is partially loaded or symmetriclly loaded,the corresponding results are same. Theshear sharing ratios are below82%for the actual bridges in the live load, and the ratios changes with the change of the cross-sectional position.3) Compared with the concrete boxgirder, the partial load effect of composite box girder with corrugated steel webs is moreobvious,the coefficient of test box girder loaded partially is1.26~1.30. For entities bridgeengineerings, with the partial loads, the coefficient of the2ndbridge in Guangxi is1.21~1.42,and one of Taohuayu bridge is1.30~1.40.