超大跨径活性粉末混凝土拱桥试设计研究

发布时间：2018-05-12 12:19

本文选题：超大跨径拱桥 + 活性粉末混凝土　；参考：《福州大学》2014年硕士论文

【摘要】：制约混凝土拱桥向更大跨度发展的主要问题是,随着拱桥跨径的增大,其自重显著增大,施工难度和施工费用急剧增加,影响了其经济性。减轻混凝土拱桥结构自重有效的方法之一是采用高强、超高强的混凝土。活性粉末混凝土(RPC)是超高强混凝土中最具潜力的一种。本文进行超大跨径RPC拱桥试设计研究,从受力性能、施工性能和经济性能等方面分析了RPC在超大跨径混凝土拱桥上应用的可行性。本文的主要工作和结论归纳如下：(1)以日本600m混凝土试设计拱桥为原型,采用高强混凝土(HSC)和活性粉末混凝土(RPC)分别进行600m跨径拱桥的试设计。通过MIDAS/CIVIL2010软件建立空间有限元模型,依据《公路圬工桥涵设计规范》(JTG D61-2005)进行RPC拱桥的强度与稳定的验算。结果表明,RPC拱桥的强度、稳定性均满足要求。(2)从工程数量、拱圈截面刚度、拱圈内力与稳定性与HSC拱桥进行对比。结果表明,由于RPC超高强的材料特性,可以采用更薄的截面形式。与HSC拱桥相比,RPC拱圈截面厚度减小了47%,拱圈自重和轴力减轻了40%左右。由于RPC拱桥的自重减轻导致内力减小以及RPC材料的弹性模量比HSC拱桥的大,使得RPC拱桥的纵横向稳定系数较HSC拱桥有一定的提高。(3)试设计拱桥选取了两阶段成拱的悬臂拼装法进行施工,充分发挥RPC轻质高强的特性,使其预制节段和节段接缝大大减少,并降低起重设备和扣索用量,加快了施工进度,较其他施工方法具有明显优势。(4)对RPC拱桥的施工阶段应力、扣索索力进行计算,并进行施工阶段的稳定性分析。结果表明,采用零位移法进行扣索索力计算可保证拱肋的线形始终在设计轴线上,且有利于施工过程中的几何线形的控制；施工过程中拱圈的压应力和拉应力均小于RPC材料容许值；施工阶段的稳定安全系数均满足规范要求。(5)借鉴国内外桥梁全寿命周期成本研究成果,对RPC拱桥和HSC拱桥进行全寿命周期成本的分析与计算,并重点分析桥梁全寿命周期成本中的维修加固成本和用户成本。分析结果表明,RPC桥的建设成本为HSC桥的1.30倍,加上营运期成本,以及拆除成本的全寿命周期成本仅为HSC拱桥的0.60倍。从上述的研究结果来看,超大跨径RPC拱桥从结构受力性能、施工性能和经济性能方面而言均是可行的。
[Abstract]:The main problem restricting the development of concrete arch bridge to a larger span is that with the increase of span of arch bridge the weight of concrete arch bridge increases significantly and the construction difficulty and construction cost increase sharply which affects its economy. One of the effective ways to reduce the dead weight of concrete arch bridge is to adopt high strength and super high strength concrete. Reactive powder concrete (RPC) is the most potential type of super-high-strength concrete. In this paper, the experimental design of super-span RPC arch bridge is carried out, and the feasibility of application of RPC in super-span concrete arch bridge is analyzed from the aspects of mechanical performance, construction performance and economic performance. The main work and conclusions of this paper are summarized as follows: (1) the experimental design of 600m span arch bridge is carried out by using high strength concrete (HSC) and reactive powder concrete (RPC), respectively, taking 600m concrete trial design arch bridge as prototype. The spatial finite element model was established by MIDAS/CIVIL2010 software, and the strength and stability of the RPC arch bridge were checked according to the Design Code of Highway masonry Bridge and culvert (JTG D61-2005). The results show that the strength and stability of HSC arch bridge meet the requirements. 2) the number of projects, the stiffness of arch ring section, the internal force and stability of arch ring are compared with that of HSC arch bridge. The results show that because of the properties of RPC ultra-high strength material, a thinner cross section can be adopted. Compared with HSC arch bridge, the thickness of arch ring section is reduced by 47%, and the dead weight and axial force of arch ring are reduced by about 40%. As the weight of RPC arch bridge decreases, the internal force decreases and the elastic modulus of RPC material is larger than that of HSC arch bridge. The longitudinal and transverse stability coefficient of RPC arch bridge is improved to some extent compared with that of HSC arch bridge. The arch bridge is designed and constructed by using two-stage arch cantilever assembly method to give full play to the light-weight and high-strength characteristics of RPC, so that the prefabricated segments and joints are greatly reduced. It also reduces the amount of hoisting equipment and cable buckling, accelerates the construction progress, and has obvious advantages over other construction methods. It calculates the stress and cable buckling force of RPC arch bridge in construction stage, and analyzes the stability of the construction stage. The results show that the calculation of cable buckling force by zero displacement method can ensure the alignment of arch rib is always on the design axis and is advantageous to the control of geometric alignment in the construction process. The compressive stress and tensile stress of arch ring in construction process are less than the allowable value of RPC material, and the safety coefficient of stability in construction stage all meet the requirements of code. 5) draw lessons from the domestic and foreign bridge life cycle cost research results. The life cycle cost of RPC arch bridge and HSC arch bridge is analyzed and calculated, and the maintenance and reinforcement cost and user cost of the whole life cycle cost of the bridge are analyzed. The results show that the construction cost of HSC bridge is 1.30 times of that of HSC bridge, and the cost of operation and demolition is only 0.60 times of that of HSC arch bridge. From the above research results, it is proved that the super-span RPC arch bridge is feasible in terms of structural mechanical performance, construction performance and economic performance.
【学位授予单位】：福州大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U442.5

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