Experimental Study And Analysis On Mechanical Performance Of The Composite Box Girder Bridge With Corrugated Steel Webs

In this paper, the static and dynamic behaviors of the simply supported single-box,single–chamber girder and two-span continuous girder with corrugated steel webs are studiedsystematically by the use of theoretical analysis, numerical simulation and experimenialresults. The main work and achievements are as follows:（1）The test models of box girders with corrugated steel webs are designed andconstructed for the test. The load-disaplacement relationship, longitudinal stress distribution,natural frequencies and vibration modes of the test girders are measured, which provide theexperimental basis for the subsequent the static and dynamic characteristics analysis of thebox girder with corrugated steel webs.（2）Using the variational principle method and omitting the ability to resist bending ofcorrugated steel webs, the governing differential equation of motion and the correspondingnatural boundary condition of the box girder with corrugated steel webs are established andthe coefficients formulas of shear lag of the two-span continuous box girder with corrugatedsteel webs under uniform load and concentrated load are deduced. Combined with the resultsof the indoor model test and the ANSYS finite element analysis, the effectiveness of theformula are verified.（3）Based on considerring the effects of shear lag and shear deformation of the boxgirder with corrugated steel webs and the correction of shear modulus, using the variationalprinciple method, the deflection formulas of the simply supported box and two-spancontinuous box girder with corrugated steel webs under uniform load are deduced. Combinedwith the results of the indoor model test and the ANSYS finite element analysis, theeffectiveness of the formulas are verified. With the wide-span ratio changes of the box girderwith corrugated steel webs, the influences of shear lag and shear deformation on the simplysupported box and two-span continuous box girder with corrugated steel webs under uniformload are studies respectively.（4）When the deflection formula of the two-span continuous box girder with corrugatedsteel webs under concentrated load is deduced by the variational principle method, thedeflection caused by shear deformation can not be calculated through the second integral,because the vertical shear derivative of the cross section is zero. It is recommended that thetotal deflection of the two-span continuous box girder with corrugated steel webs underconcentrated load should be calculated the deflection of elementary beam theory and shear lageffect, directly add the the deflection produced by shear deformation. Combined with theresults of the indoor model test and the ANSYS finite element analysis, the effectiveness of the method is verified. With the wide-span ratio changes of the box girder with corrugatedsteel webs, the influences of shear lag and shear deformation on the two-span continuous boxgirder with corrugated steel webs under concentrated load are studies respectively.（5）Based on considerring the effects of shear lag and shear deformation of the boxgirder with corrugated steel webs and the correction of shear modulus, the vertical bendingvibration frequency formula of the box girder with corrugated steel webs was establishedusing the principle of minimum potential energy and the principle of Hamilton. In theformula，it is found the influencing factors of the frequency can be divided into three aspects:shear lag，shear deformation of corrugated steel webs and the coupling relationship. Theanalysis results show the shear deformation of corrugated steel webs has great influence onthe frequency and the coupling relationship and shear lag has low influences on the frequency.Combined with the results of the indoor model test and the ANSYS finite element analysis，the effectiveness of the formula is verified.（6）Based on the vertical bending vibration frequency formula of the simply supportedbox girder with corrugated steel webs, the vertical bending vibration frequencies arecalculated using break union legislation. Combined with the results of the indoor model testand the ANSYS finite element analysis, the effectiveness of the formula is verified.（7）The analysis results also show the vertical fundamental frequency of the (JTGD60-2004) does not apply to the simply supported single-box,single–chamber girder andtwo-span continuous girder with corrugated steel webs. In this paper, reasonable verticalfundamental frequency calculation formulas for the simply supported single-box,single–chamber girder and two-span continuous girder with corrugated steel webs are given.