钢—混凝土曲线组合梁弯扭作用机理及横隔板效应研究

发布时间：2018-12-06 18:53

【摘要】：钢-混凝土组合梁由于自重轻、便于架设、抗震性能好、结构稳定等优点,在中等跨径的直线桥梁及具有平曲线的曲线桥梁中得到了广泛的应用。曲线组合梁在荷载作用下会产生复杂的弯扭耦合效应,目前对这一方面的研究还有待深入。本文依托国家自然科学基金资助项目《隔板式曲线组合梁桥弯扭作用机理及横隔板影响效应研究》(51108281),针对曲线组合梁施工阶段开口钢梁的弯扭效应和使用阶段闭口组合梁的畸变效应进行了研究,主要工作及结论如下:(1)针对曲线组合梁在混凝土板浇筑过程中的曲线形开口薄壁钢梁,采用M/r法将其简化为直梁,根据符拉索夫约束扭转理论和初参数法对扭转效应进行了求解;以截面翘曲正应力和弯曲正应力的最大扭转应力比为指标,发现曲线组合梁施工阶段扭转应力比随横隔板数量的增加按指数规律下降,随跨径比的增大线性增加,随跨度的增大而减小,但受钢梁截面高度和翼缘宽度的影响很小;(2)采用M/r法将曲梁转化为直梁,在考虑钢梁和混凝土的材料差异,但不考虑结合面滑移的情况下,采用能量-变分法推导了曲线组合箱梁的畸变控制微分方程;(3)基于弹性地基梁理论建立了使用阶段曲线组合箱梁的Midas/civil模型,对影响畸变效应的因素进行了参数分析,发现曲线组合梁畸变效应随横隔板数量的增加而减小,随跨径比的增大线性增加,随跨度的增大畸变应力比减小,随钢梁腹板高度和钢梁下翼缘宽度的增大畸变角、畸变应力减小,混凝土板厚度对畸变效应基本没有影响;(4)分别给出了按照施工阶段开口截面约束扭转理论和使用阶段闭口截面畸变理论得到的曲线组合梁横隔板间距计算公式,其中可以考虑组合梁的曲线半径、跨度、以及希望设定的扭转或畸变应力比。曲线组合梁的横隔板间距可按两个公式计算结果的较小值取用。
[Abstract]:Steel-concrete composite beams are widely used in straight bridges with medium span and curved bridges with flat curves due to their advantages of light weight, easy erection, good seismic performance and structural stability. The bending and torsional coupling effect of curved composite beam is complex under load, and the research on this aspect needs to be further studied at present. This paper relies on the project supported by the National Natural Science Foundation of China < Research on bending and torsion Mechanism of curved Composite girder Bridges with diaphragm Type and influence effect of Transverse Barrier Board "(51108281), In this paper, the bending and torsion effect of open steel beam in construction stage and the distortion effect of closed composite beam in use stage are studied. The main work and conclusions are as follows: (1) for curved thin-walled steel beams with curved openings during concrete slab pouring, the method of M / r is used to simplify them to straight beams. The torsion effect is solved according to the theory of torsion constrained by Vlasov and the method of initial parameters. Taking the maximum torsional stress ratio of the section warping normal stress and bending normal stress as the index, it is found that the torsional stress ratio decreases exponentially with the increase of the number of transverse partitions in the construction stage of curved composite beams, and increases linearly with the increase of span ratio. It decreases with the increase of span, but it is little affected by the section height and flange width of steel beam. (2) the curved beam is transformed into a straight beam by using the M / R method. Considering the material difference between steel beam and concrete, but not considering the slip of the interface, the distortion control differential equation of curved composite box girder is derived by the energy-variational method. (3) based on the theory of elastic foundation beam, the Midas/civil model of curved composite box girder in use stage is established. The parameter analysis of the factors affecting the distortion effect is carried out. It is found that the distortion effect of the curved composite beam decreases with the increase of the number of transverse diaphragm. With the increase of span ratio, the distortion stress ratio decreases with the increase of span, the distortion angle decreases with the increase of steel beam web height and the width of lower flange of steel beam, the distortion stress decreases, and the thickness of concrete slab has no effect on the distortion effect. (4) according to the theory of constrained torsion of open section in construction stage and the theory of distortion of closed section in use stage, the calculation formulas of transverse diaphragm spacing of curved composite beam are given respectively, in which the radius of curve and span of composite beam can be taken into account. And the desired torsional or distorted stress ratio. The distance between transverse spacers of curved composite beams can be obtained by the smaller value of the results calculated by two formulas.
【学位授予单位】：石家庄铁道大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U441

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