考虑腹板剪切变形的波形钢腹板组合箱梁剪力滞效应分析

Analysis on shear-lag effect of composite box girders with corrugated steel webs considering shear deformation of webs

在波形钢腹板组合箱梁中,剪力主要由波形钢腹板承担。由于波形钢腹板的抗剪刚度比混凝土腹板有较大程度的降低,波形钢腹板会产生较大的竖向剪切变形。为此,基于能量变分法建立了考虑腹板剪切变形的波形钢腹板组合箱梁剪力滞效应分析方法。通过试验对该理论分析方法进行验证,并基于该理论分析方法研究波形钢腹板剪切变形对剪力滞效应的影响。同时,基于该分析方法提出了采用影响线最不利加载方式进行相关规范中规定的汽车荷载作用下的波形钢腹板组合箱梁桥剪力滞效应分析。结果表明:考虑腹板剪切变形的分析方法与试验结果吻合度良好;波形钢腹板的剪切变形有利于减轻三跨连续梁正弯矩区的剪力滞效应,即考虑腹板剪切变形后翼缘有效宽度系数值更接近于1。

In a composite box girder with corrugated steel webs,the shear force is mainly carried by the webs.As the shear rigidity of corrugated steel webs is smaller than that of concrete webs,larger shear deformation will be generated in corrugated steel webs.Therefore,an analytical analysis method was first proposed to analyze the shear-lag effect of composite girders with corrugated steel webs,in which the influence of shear deformation of webs was considered.The analytical method was validated by the experimental research,and the influence of shear deformation of webs was studied using this analytical method.Meanwhile,the shear-lag effect of this kind of structure under the vehicle loading specified in design codes was investigated considering the most unfavorable loading condition based on the concept of the influence line.The results show that the results of the proposed analytical method agree well with experimental results.The shear deformation of webs reduces the shear-lag effect in the positive bending moment segments of the three-span continuous beam.To be specific,when the shear deformation of webs is considered,the effective flange width coefficient becomes closer to 1.0.