连续钢-混组合梁负弯矩区裂缝控制设计与研究

Design and Research on Crack Control in Negative Moment Zone of Continuous Steel-Concrete Composite Beams

摘要:

连续钢-混组合梁因具有跨越能力强、施工效率高和经济性良好等优势，被广泛应用于城市高架桥和跨线桥等工程中。以宁波世纪大道快速路南延工程35.5 m+56.0 m+40.5 m连续钢-混组合梁为工程背景，利用有限元软件MIDAS Civil建立全桥梁单元模型，研究桥面板配筋率、混凝土浇筑顺序以及中支点顶升高度等因素对连续组合梁负弯矩区桥面板和钢梁的影响。结果表明：在中小跨径连续组合梁中，桥面板配筋率、混凝土浇筑顺序及中支点顶升高度对中支点负弯矩效应均具有较为显著的影响；提高负弯矩区桥面板配筋率可有效控制桥面板裂缝宽度，与中支点顶升效果相同，但该措施施工更为简便、工程造价更低，具有较好的工程适用性。

Abstract:

Continuous steel-concrete composite beams are widely used in urban viaducts and overpass projects due to their advantages such as strong spanning capability, high construction efficiency, and good economic performance. Based on the engineering project of 35.5 m+56.0 m+40.5 m continuous steel-concrete composite beams in the Ningbo Century Avenue Expressway South Extension Project, a full-bridge element model is established using the finite element software MIDAS Civil to study the effects of factors such as deck reinforcement ratio, concrete pouring sequence, and the jacking height at intermediate supports on the deck and steel girders in the negative moment zone of continuous composite beams. The results show that in small and medium-span continuous composite beams, the reinforcement ratio of the bridge deck slab, the concrete pouring sequence, and the jacking height of the mid-support all have a significant impact on the negative bending moment effect at the mid-support. Increasing the reinforcement ratio in the negative moment zone of the bridge deck can effectively control the crack width of the deck, achieving an effect similar to that of support jacking. However, this measure is simpler to construct and incurs lower project costs, demonstrating better applicability in engineering practice.