新型空心管状翼缘钢板组合梁设计理念与力学性能

The Design Concept and Mechanical Performance of Novel Bridge Composite Girders Using Hollow Tubular Flanges

工字钢组合梁桥正朝着少主梁、精简横向联系的方向发展。与传统多主梁复杂横向联系组合梁桥相比,双主梁桥由于采用了开口截面的结构形式,极大地削弱了其抗扭能力,在偏载作用下会产生较大的变形及翘曲应力,使钢主梁处于弯扭耦合的受力状态。空心管状翼缘钢板组合梁采用空心钢管取代传统的平板上翼缘,提升了稳定性,改善了结构性能。本文通过理论分析和实体有限元法的计算,研究了单梁在自重与横向风荷载作用下的稳定性;对非组合截面的组合体系下的稳定性能进行了分析与比较,并分离出扭转翘曲应力和纵向正应力,研究了不同跨径下扭转效应的影响。最后,对横向联系、加劲肋的影响进行了分析。研究结果表明,空心管状翼缘钢板组合梁桥扭转刚度大于传统工字形截面组合梁扭转刚度,自身横向稳定性好,并且需要较少的横向联系与加劲肋,可实现单梁吊装,避免采用过多临时加固及支撑措施,提高施工效率。

Compared with traditional multi-girder systems,the steel plate composite beam bridge with double girder system simplifies the construction process,saves material consumption and has better economic advantages.However,due to the low torsional stiffness and poor stability of the traditional I-section,more lateral connections are needed to form a frame to ensure the safety and performance during the construction process.Innovative bridge girders with hollow tubular flanges are proposed in the paper to replace the flange plate of traditional I-section with the flange of hollow rectangular tube,which improves the torsional stiffness of traditional I-section,and the bending performance is nearly unchanged.In this paper,the stability of individual girders under self-weight and transverse wind load is investigated by using finite element method;the stability of non-combined sections is analyzed and compared,and the warping normal stress and primary bending normal stress are separated to study the influence of torsional effect.Finally,the effects of transverse connections and stiffeners are analyzed.The results show that the torsional stiffness of the hollow tubular flange girder bridge is greater than that of the traditional I-section composite girder with greater stability,and it needs fewer transverse connections and stiffeners,thus,it can realize the individual girder lifting and avoiding the use of temporary supports or shoring to improve the construction efficiency.