核心混凝土脱空对钢管混凝土拱肋面内稳定的影响

发布时间：2018-04-27 23:42

本文选题：钢管混凝土 + 拱肋　；参考：《吉林建筑大学》2017年硕士论文

【摘要】：钢管混凝土拱是一种钢-混凝土组合结构。承载力高,跨越能力强的优点使其广泛应用于大跨拱桥的建设之中。但通过对已建成拱桥的检测,发现拱肋的混凝土存在不同程度的脱空现象,脱空影响拱肋的稳定性,为拱桥的安全运营带来隐患。现行规范规程在计算拱肋面内承载力时,对脱空考虑不充分,侧重于采取施工措施对其进行防治。本文就脱空对拱肋面内稳定性的影响展开了研究,具体内容如下:(1)采用ANSYS建立钢管混凝土拱肋有限元模型,将有限元分析结果与试验结果进行对比,发现两者基本吻合,验证了有限元模型的可靠性。对比了相同脱空率下纵向、径向、球冠型三种脱空截面形式的有限元分析结果,确定了合理的脱空截面计算模型。对全跨、半跨均布多点集中力作用下的抛物线拱、悬链线拱、圆弧线拱进行了内力分析,确定了拱肋的受力性质。(2)归纳总结了现行四部可用于设计钢管混凝土拱肋的规范规程。以四部规范规程对脱空拱肋进行设计,并与有限元分析结果进行对比,考察四部规范规程对脱空拱肋设计的安全性。(3)拱肋在全跨、半跨均布多点集中力作用下为压弯构件,宜采用M-N相关方程对其进行设计。本文考虑矢跨比、含钢率、混凝土强度、钢材强度和长细比五个参数,对1116个钢管混凝土拱肋的模型进行了有限元分析,对《拱形钢结构技术规程》(JGJ/T249-2011)的设计公式进行修正,将修正后公式的设计结果与有限元分析结果进行对比,验证了本文修正后公式的可靠度。
[Abstract]:Concrete filled steel tube arch is a kind of steel-concrete composite structure. The advantages of high bearing capacity and strong span capacity make it widely used in the construction of long span arch bridge. However, through the inspection of the arch bridge, it is found that the concrete of arch rib has different degree of void phenomenon, which affects the stability of arch rib and brings hidden trouble to the safe operation of arch bridge. In calculating the bearing capacity of arch rib plane, the current code is not enough to consider the void, and puts emphasis on taking construction measures to prevent and cure it. In this paper, the effect of void removal on the stability of arch rib surface is studied. The concrete arch rib model is established by ANSYS. The finite element analysis results are compared with the experimental results, and it is found that the two models are in good agreement with each other. The reliability of the finite element model is verified. The finite element analysis results of longitudinal, radial and spherical cross sections with the same void ratio are compared, and a reasonable calculation model of void section is established. The internal forces of parabola arch, catenary arch and circular arc arch under the action of multi-point concentrated force are analyzed, and the mechanical properties of arch rib are determined. By comparing with the results of finite element analysis, the safety of the four-part code for the design of the empty arch rib is investigated. The arch rib is a bending member under the action of full span, half span uniform distribution and multi-point concentrated force. M-N correlation equation should be used to design it. In this paper, considering the five parameters of rise-span ratio, steel ratio, concrete strength, steel strength and slenderness ratio, the finite element analysis of 1116 concrete filled steel tubular arch ribs is carried out, and the design formula of JGJ / T249-2011) is revised. The design results of the modified formula are compared with the results of finite element analysis, and the reliability of the modified formula is verified.
【学位授予单位】：吉林建筑大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U441;U448.22

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