钢箱梁桥相对支座位置纵向偏移施工误差限值研究

Research on Construction Error Limit of Longitudinal Offset of Steel Box Girder Bridge Relative to Bearing Position

针对钢箱梁体支座设计位置相对偏移误差,建立钢箱梁的全桥模型,研究不同支座位置偏移情况下的局部变形和应力。通过提取跨中、支座上方顶板竖向变形,分析支座偏差对顶板结构位移的影响。基于横隔板、加劲构件和底板交界处的应力,研究不同支座偏差下局部峰值应力的变化规律。结果表明,梁体相对支座偏移对钢箱梁顶板与横隔板变形及受力的影响较小。竖向加劲板与底板均在支座偏移50 mm后,构件峰值应力及局部应力增幅显著,顶推施工中应重点监测。考虑到竖向加劲板为支座偏差下的钢箱梁最不利构件,建议取50 mm为支座偏移限值,以确保顶推施工安全,但具体偏移限值需参考实际施工。

Aiming at the relative deviation error of designed location for the bearing in the steel box girder,a full bridge model of the steel box girder was established.The local deformation and stress under different bearing deviations were studied.The influence of bearing deviation on roof displacement was analyzed by extracting the vertical deformation of the roof over the middle span and bearing.Based on the stress at the junction of diaphragm,stiffener and bottom plate,the variation law of peak stress under different bearing deviations was studied.The results showed that the displacement of the beam relative to the bearing had little influence on the deformation and stress of the roof and diaphragm of the steel box girder.When the vertical stiffener and bottom plate were shifted 50 mm,the peak stress and local stress of components increased sharply,which should be mainly monitored in incremental launching construction.Considering that the vertical stiffener was the most unfavorable component of the steel box girder under the bearing deviation,it was suggested to set 50 mm as the offset limit of the bearing to ensure the safety of the incremental launching construction,but the specific offset limit should refer to the actual construction.