某混凝土拱桥加固工程优化设计研究

发布时间：2018-08-16 17:08

【摘要】：本文以红水河大桥为研究对象,针对该桥存在的桥面板底部开裂、主拱圈出现径向裂缝、波顶纵向缝、盖梁和底梁底部裂缝等病害,对这些病害提出多种加固方案,通过计算分析来对加固方案进行比选和优化,进而提出一个较为合理的加固方法,使其既能满足承载能力的需求,又能使加固更加经济合理。 (1)本文首先对本桥存在的病害进行病因分析,为进一步提出合理的加固方法提供依据。 (2)针对本桥桥面板底部出现裂缝,提出采用粘贴钢板法和碳纤维布法来对桥面板进行补强处理,并对这两种方法进行承载能力计算和经济适用性比较。通过计算,当采用这两种方法使桥面板的跨中达到相同的抗弯能力时,其采用粘贴碳纤维布的经济性能要好一些；但通过对其斜截面抗剪能力进行计算时发现,底部采用粘贴钢板法比采用粘贴碳纤维布法能更好的提高其抗剪能力。因此选用粘贴钢板法对桥面板进行加固。 (3)针对本桥主拱圈出现径向裂缝,两边箱型拱肋板出现混凝土开裂、脱落及露筋等病害以及横向联系梁出现开裂。提出对本桥主拱圈和横向联系的加固方法,横向联系采用粘贴钢板法,在横向联系梁和拱肋开裂处加固使其刚性连接。主拱圈的加固方法根据设计方案采用两边箱型拱肋进行粘贴钢板法和粘贴碳纤维布法。通过对本桥加固后的静力分析和移动荷载时程分析,采用粘贴钢板法比采用粘贴碳纤维布的主拱圈跨中挠度和桥梁纵向的应力水平较小；而对其进行模态分析和屈曲稳定性分析表明,粘贴钢板加固后对结构刚度和稳定性的提升要高于采用粘贴碳纤维布法,基于以上分析最终采用粘贴钢板法来对本桥的主拱圈进行加固。 (4)针对以上分析,在上面方案基础上对其横向联系梁的加固进行优化研究,优化采用两种方案来进行：一是只对部分横向联系梁进行加固；二是根据一方案的计算结果来进行更进一步的优化研究,不对横向联系梁进行加固。通过对两种方案的静力和动力分析表明：当只对部分横向联系梁进行加固时,结构在静力分析时,拱桥跨中的挠度和纵向应力与原设计计算值差别很小；动力分析时,结构的基频和稳定性系数分别降低了11%和17%。当不对横向联系梁进行加固时：结构在静力分析时,结构的挠度和桥梁纵向应力值比原设计值大；动力分析时,结构的基频和稳定性系数分别降低了33%和41%。而且当不对横向联系进行加固时,其稳定系数值小于规范规定值,因此第二种优化结果是偏不安全的。 (5)基于以上分析,最终采用桥面板使用粘贴钢板法、主拱圈拱圈粘贴钢板法和对部分横向联系进行加固的设计方法。
[Abstract]:In this paper, Hongshuihe Bridge is taken as the research object. In view of the cracks in the bottom of the bridge deck, radial cracks in the main arch ring, longitudinal cracks in the wave top, cracks in the cover beam and the bottom of the bottom beam of the bridge, various reinforcement schemes are put forward for these diseases. Through calculation and analysis, the reinforcement scheme is compared and optimized, and a more reasonable reinforcement method is put forward, which can meet the demand of carrying capacity. It can also make the reinforcement more economical and reasonable. (1) this paper firstly analyzes the causes of the diseases existing in the bridge, and provides the basis for further putting forward a reasonable reinforcement method. (2) aiming at the cracks at the bottom of the bridge deck, In this paper, the method of sticking steel plate and the method of carbon fiber arrangement are put forward to reinforce the bridge deck, and the load-carrying capacity and economic applicability of these two methods are calculated and compared. Through calculation, when the two methods are used to achieve the same flexural capacity in the span of the deck slab, the economic performance of the composite carbon fiber sheet is better, but it is found that the shear resistance of the inclined section is calculated. The shear resistance can be improved better by sticking steel plate method at the bottom than by using carbon fiber cloth method. Therefore, the method of sticking steel plate is used to reinforce the deck slab. (3) aiming at the radial crack of the main arch ring of the bridge, the concrete cracking of the box-shaped arch ribbed slab on both sides, the disease of shedding and exposing reinforcement, and the cracking of the transverse connection beam. The method of strengthening the main arch ring and transverse connection of the bridge is put forward. The transverse connection is strengthened with steel plate method and the rigid connection is strengthened at the crack of the transverse connection beam and arch rib. According to the design scheme, the main arch ring is reinforced with steel plate and carbon fiber. Through the static analysis and moving load time history analysis of the bridge after strengthening, the deflection of the main arch ring span and the longitudinal stress level of the bridge are smaller by the method of sticking steel plate than by using the carbon fiber cloth. The modal analysis and buckling stability analysis show that the stiffness and stability of the structure strengthened by bonded steel plate are higher than that of carbon fiber reinforced concrete. Based on the above analysis, the method of sticking steel plate is used to strengthen the main arch ring of the bridge. (4) in view of the above analysis, the reinforcement of the transverse connection beam is optimized on the basis of the above scheme. The optimization is carried out by two schemes: one is to reinforce only some transverse connecting beams; the other is to carry out further optimization research according to the calculation results of one scheme and not to reinforce the transverse connecting beams. Through the static and dynamic analysis of the two schemes, it is shown that the deflection and longitudinal stress in the span of the arch bridge are very little different from the calculated values of the original design when only some transverse connecting beams are strengthened, and the dynamic analysis results show that the deflection and longitudinal stress in the span of the arch bridge are different from those calculated in the original design. The fundamental frequency and stability coefficient of the structure are reduced by 11% and 17%, respectively. When the transverse connecting beam is not strengthened, the deflection of the structure and the longitudinal stress of the bridge are larger than those of the original design in static analysis, and the fundamental frequency and stability coefficient of the structure are reduced by 33% and 41% respectively in dynamic analysis. Moreover, when the transverse connection is not strengthened, the stability coefficient is less than the specified value, so the second optimization result is not safe. (5) based on the above analysis, the method of sticking steel plate is used in the bridge deck. The main arch ring is bonded with steel plate method and the design method of strengthening some transverse connections.
【学位授予单位】：广西大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U448.22;U445.72

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