混凝土徐变对劲性骨架拱桥稳定性影响分析

发布时间：2018-04-25 15:34

本文选题：劲性骨架拱桥 + 稳定性　；参考：《重庆交通大学》2015年硕士论文

【摘要】：本文以主跨为416 m上承劲性骨架拱桥为工程背景,在现有混凝土结构徐变稳定性分析理论的基础上,对大跨度劲性骨架拱桥徐变稳定性进行了深入研究,主要研究工作如下:①通过混凝土结构徐变稳定性理论研究,得出了杆系结构有限元徐变稳定通用方法,在此基础上,提出了通过引用按龄期调整有效模量法与有限元软件Midas/civil结合的方法求解结构徐变稳定性的实用算法。通过对比轴心受压柱徐变稳定的理论计算值与本文所提出方法的计算结果以及对比参考文献中的单圆管钢管混凝土拱助算例结果与本文所提出方法的计算结果,验证了本文提出方法的正确性。②以主跨为416 m上承式钢筋混凝土拱桥为工程背景,分析了混凝土徐变对劲性骨架拱肋施工阶段静力性能的影响。运用本文提出的方法研究了混凝土徐变对劲性骨架拱肋施工阶段稳定性的影响,结果表明:徐变对结构竖向位移产生较明显的影响,拱顶截面的徐变位移所占比值从最初的3.6%增长到拱肋成型阶段时的31.0%。随着施工阶段的进行,拱圈混凝土所起到的承压作用越来越明显,稳定系数总体上呈逐渐增大趋势。③采用本方法,研究了混凝土徐变对大跨度劲性骨架拱桥成桥后结构的力学性能及稳定性的影响。结果表明:混凝土徐变效应在前10年对拱肋竖向位移的影响十分显著,相比之下,在拱肋成型10年之后,竖向位移的增值越来越小,趋于稳定。混凝土徐变效应的影响下,钢管混凝土劲性骨架拱肋的稳定性在成桥后10年内下降最为明显,第十年时稳定系数下降了36%。10年之后,拱肋的稳定系数下降缓慢,到第50年时,稳定值下降接近40%。
[Abstract]:In this paper, the creep stability of large-span rigid frame arch bridge is deeply studied on the basis of the existing theory of creep stability analysis of concrete structures, with the main span of 416m bearing rigid skeleton arch bridge as the engineering background. The main research work is as follows: through the theoretical study of creep stability of concrete structures, a universal finite element creep stability method for bar structures is obtained, and on this basis, A practical method for calculating the creep stability of structures is presented by using the method of adjusting effective modulus according to the age and the finite element software Midas/civil. By comparing the calculated values of creep stability of axially compressed columns with the results of the method presented in this paper, and comparing the calculation results of concrete filled steel tubular concrete filled steel tube arch with those of the method presented in this paper, The correctness of the method proposed in this paper is verified. 2. Based on the engineering background of 416m supported reinforced concrete arch bridge with main span of 416m, the influence of the static behavior of concrete creeping skeleton arch rib in construction stage is analyzed. By using the method proposed in this paper, the effect of concrete creep on the stability of the arch rib during construction is studied. The results show that the creep has an obvious effect on the vertical displacement of the structure. The ratio of creep displacement of arch section increased from 3.6% to 31.0% in the forming stage of arch rib. With the development of construction stage, the bearing pressure of arch ring concrete becomes more and more obvious, and the stability coefficient of arch ring concrete increases gradually with the use of this method. The effect of concrete creep on the mechanical properties and stability of long-span rigid frame arch bridge after completion is studied. The results show that the concrete creep effect has a significant effect on the vertical displacement of arch rib in the first 10 years, but after 10 years of arch rib forming, the increment of vertical displacement becomes smaller and more stable. Under the influence of concrete creep effect, the stability of concrete-filled steel tubular rigid skeleton arch rib decreases most obviously within 10 years after the bridge is completed, and the stability coefficient of arch rib decreases slowly after 36.10 years in the tenth year, and the stability coefficient of arch rib decreases slowly at the fiftieth year. The stable value drops by nearly 40.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U441;U448.22

【参考文献】