双箱单室曲线钢箱梁桥的不同建模方法计算结果对比分析

Comparison and Analysis of Different Modeling Methods for Two Box Single Room Curved Steel Box Girder Bridges

曲线钢箱梁比直线钢箱梁多了曲线弯曲引起的偏载效应,因双箱单室结构各箱室之间受力的分担比例发生变化,致使其比单箱单室曲线钢箱梁的受力要复杂。在计算分析中若采用常规的单梁模型或梁格模型,不能完全真实反映实际受力情况。为了解决双箱单室曲线钢箱梁在自重、升温、基本组合等工况下的应力分布,以2×61 m的连续钢箱梁为研究对象,建立板单元模型、梁单元模型、梁格模型分别计算并对结果进行对比分析。结果表明:1)自重作用下单梁模型不能考虑横向分布效应,其误差较大; 2)整体升温作用下单梁模型计算结果比板单元大,而梁格模型计算结果比板单元小; 3)组合后单梁模型最大误差达到10%,梁格模型达到7%,设计中不能忽略。

Curved steel box girder has more eccentric load effect caused by curved curve than linear steel box girder.The proportion of force sharing between each box of double-box single-chamber structure will change,and it is also more affected than single-chamber curved steel box girder.The force is complicated.In the calculation analysis,if the conventional single beam model or lattice model is used,the actual stress condition cannot be completely reflected.In order to figure out the stress distribution of the double-box curved steel box girder under the conditions of self-weight,temperature rise,and basic load,the continuous steel box girder with a diameter of2×61m is taken as the research object,this paper sets up the plate element model,the beam element model and the beam lattice model and calculates these models respectively,then makes a comparative analysis on the calculation.The results show:1)the single beam model under the effect of self-weight without considering the lateral distribution effect and its error is large;2)the results of the single beam model are larger than those of the plate element under the effect of global warming,while the results of the beam lattice model are smaller than the plate element;3)under the effect of basic load,the combined single beam model has a maximum error of10%and the lattice model of7%,which cannot be ignored in the design.