既有钢筋混凝土梁桥钢箱加固设计方法研究

发布时间：2018-06-30 09:01

本文选题：钢箱加固法 + 钢—混凝土组合梁　；参考：《兰州交通大学》2015年硕士论文

【摘要】：钢箱加固法是在钢—混凝土组合梁基础上发展起来的一种新型加固方法,结合了粘钢加固法和增大截面加固法的优点。钢箱加固法首先在梁底锚粘由钢板焊接成的H形钢套箍,然后在H形钢套箍下缘焊接一层钢板,使H形钢套箍下部成为一个封闭的钢箱,通过锚固螺栓和粘结剂将钢箱和原混凝土梁形成整体,可以提高桥梁结构的刚度和承载能力。钢箱加固法具有施工周期短、施工工艺简单、加固刚度大等优点,在实际工程中具有广泛的应用前景。采用钢箱法加固后的钢筋混凝土梁属于钢箱—混凝土组合结构,本文根据弹性理论和塑性理论,运用钢—混凝土组合梁的原理,分析了钢箱加固梁的抗弯和抗剪承载能力,推导了相应的理论计算公式。以矩形截面钢筋混凝土梁为研究对象,建立ANSYS有限元模型,对钢箱加固梁的力学行为及加固效果进行分析。通过对12片不同钢箱和侧板高度加固梁的有限元模型进行对比分析,讨论钢箱和侧板高度的变化对加固效果的影响。根据钢—混凝土组合梁的特点,分析了二次受力、剥离破坏、滑移效应、结构胶老化及螺栓强度等因素对钢箱加固梁承载能力的影响。以兰州市东岗立交桥引桥为工程背景,分析该桥的主要病害及形成机理,通过该桥钢箱法加固前后的静、动载试验结果的对比分析,对钢箱加固法的加固效果进行评价。实践证明,钢箱加固法不仅能有效提高钢筋混凝土梁的抗弯和抗剪承载力,增大加固梁的刚度,还能有效改善梁的受力性能,降低加固梁的跨中挠度。该加固法具有良好的加固效果,可以推广应用于类似桥梁的加固工程中。
[Abstract]:The steel box strengthening method is a new strengthening method developed on the basis of steel-concrete composite beam, which combines the advantages of the steel bonded reinforcement method and the reinforcement method of increasing section. The steel box reinforcement method first adheres to the H-shaped steel collar welded by the steel plate at the bottom of the beam, and then welds a layer of steel plate at the lower edge of the H-shaped steel collar, so that the lower part of the H-shaped steel collar becomes a closed steel box. The stiffness and bearing capacity of the bridge structure can be improved by forming the steel box and the original concrete beam as a whole by anchoring bolts and binders. The steel box reinforcement method has the advantages of short construction period, simple construction technology and large reinforcement stiffness. It has a wide application prospect in practical engineering. The reinforced concrete beam strengthened by steel box method belongs to steel box concrete composite structure. According to the theory of elasticity and plasticity, the flexural and shear bearing capacity of steel box strengthened beam is analyzed according to the theory of elasticity and plasticity. The corresponding theoretical formulas are derived. Taking reinforced concrete beam with rectangular section as the research object, the finite element model of ANSYS is established to analyze the mechanical behavior and strengthening effect of steel box reinforced concrete beam. By comparing and analyzing the finite element model of 12 beams strengthened with different steel box and side slab height, the influence of the change of steel box and side slab height on the reinforcement effect is discussed. According to the characteristics of steel-concrete composite beams, the effects of secondary force, debonding failure, slip effect, aging of structural glue and bolting strength on the bearing capacity of steel box strengthened beams are analyzed. Taking the approach bridge of Donggang overpass in Lanzhou as the engineering background, the main diseases and formation mechanism of the bridge are analyzed. Through the contrast analysis of the static and dynamic test results before and after the reinforcement of the steel box method, the reinforcement effect of the steel box reinforcement method is evaluated. The practice shows that the steel box strengthening method can not only effectively improve the flexural and shear bearing capacity of reinforced concrete beams, but also can effectively improve the mechanical behavior of the strengthened beams and reduce the mid-span deflection of the strengthened beams. The reinforcement method has a good effect and can be applied to similar bridge reinforcement projects.
【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U445.72

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