钢-混凝土组合脊骨梁中大悬臂挑梁荷载分布的空间有限元分析及简化计算研究

SFEM Analysis and Study on Simplified Calculation for Load Distributions on Long Cantilevered Beams of Steel-Concrete Composite Spine Girder

首先采用空间有限元方法,对长沙市洪山大桥的钢-混凝土组合脊骨主梁中大悬臂钢挑梁间的荷载分布规律进行了计算分析,并探讨了荷载作用位置对挑梁荷载分布的影响,得出钢挑梁荷载分布可以采用3片梁分析模型进行计算的结论;然后提出了考虑挑梁刚度沿其纵向变化和混凝土行车道板受钢箱梁约束程度影响的弹性支承连续梁平面简化算法来分析挑梁间的荷载分布,并将沿横桥向布置的多排车轮荷载用一个等效集中荷载代替。对比分析表明平面简化算法具有较高的精度,简单可行。

In this paper, the load distributions on long cantilever steel beams of the steel-concrete composite spine main girder of Hongshan Bridge located in Changsha City, are first calculated by using the spatial finite element method, the influence of load distributions on the cantilevered beams by the variation of load application point is analyzed, and it is educed that a analysis model of three beams for calculating the load distributions is acceptable. And then, a simplified calculation method of plane of elastic support continuous beam considering the variation of stiffness of cantilevered beams and how the steel box girder to restraint concrete slabs is proposed in calculation of the load distribution, and a few wheel loads distributing along the lateral direction of the bridge can be replaced by an equivalent concentrated load. Comparison of the above methods indicates that the simplified calculation method of plane is of a good precision and is feasible.