大跨度变截面波形钢腹板组合连续箱梁桥剪力滞效应研究

Shear Lag Effect of Long Span Composite Continuous Box-Girder Bridge with Corrugated Steel Webs and Variable Cross-section

目的确定影响剪力滞系数的主要几何参数,总结计算翼缘有效宽度比的经验公式.方法基于有限元软件Midas/FEA,计算集中(均布)荷载作用下腹板厚度、顶板厚度、荷载类型、宽跨比等因素对大跨度变截面波形钢腹板组合连续箱梁剪力滞效应的影响,找出其中对剪力滞效应有主要影响的几何参数,利用数据回归分析方法研究翼缘有效分布宽度取值问题.结果剪力滞效应受荷载作用类型影响较大.明确宽跨比是影响箱梁剪力滞效应的主要几何参数.结论建立了集中荷载作用下波形钢腹板组合箱梁翼缘有效分布宽度计算的经验公式.

In order to confirm the primary geometric parameter of shear lag effect and establish experiential formulas of effective width ratio, shear lag effect of long-span composite continuous boxgirder bridge with corrugated steel webs and variable cross-section were analyzed. Based on finite element analysis software Midas/FEA, the influencing factors such as web thickness, top slab thickness, load form,width-span ratio,were analyzed under concentrated load condition and uniform load conditions. Then the primary geometric parameters of all were found out,and the theoretical value for effective flange width were discussed based on polynomial regression method. The results show that load type had great influence on shear lag effect; Width-span ratio was confirmed as the mainly factor working on shear lag effect among all the geometric parameters. Finally, theexperiential formulas of the effective flange width ratio under concentrated load were put forward with the only factor of width span ratio.