逐级套箍加固大跨坦拱桥效果后评估技术及应用

发布时间：2018-02-02 15:31

本文关键词： 大跨坦拱桥加固技术逐级套箍法加固后效果评估极限状态设计法指标体系静力荷载试验刚度评估指标体系　出处：《重庆交通大学》2015年硕士论文　论文类型：学位论文

【摘要】：拱桥是西部公路在役桥梁的主力桥型,其中跨越大江深谷的大跨坦拱桥占有较大的比重。大跨坦拱桥由于自重大、具有一定梁式桥的受力倾向,其加固技术的研发一直是桥梁加固课题的难点,亟待攻克。相应,构建大跨坦拱桥的评价指标体系也就显得重要和迫切。本文针对钢筋混凝土肋拱桥采用逐级套箍技术的加固效果后评估研究,介绍了逐级套箍加固大跨坦拱桥技术的加固机理、设计计算方法与施工工艺,结合静力荷载试验提出了采用该技术加固后桥梁的实际效果的后评估强度和刚度指标,并结合工程实例进行验证。主要研究内容包括:①基于荷载横向分布、截面增大、逐级叠加受力和断裂力学机理,结合极限状态设计法,分析了逐级套箍加固大跨坦拱桥技术的设计理论和方法,同时介绍了该项加固技术的施工工艺。②基于加固前后结构强度和刚度及其变化,建立了大跨坦拱桥加固效果后评估的指标体系:根据加固前后结构承载力变化、恒载应力变化、恒载荷载增加与活载变化幅度以及加固层的受力水平,提出了四项指标——承载力提高率αL(或αL')、恒载应力变化率αD、荷载置换率αT、加固层利用率αM,探讨四项指标的工程意义和作用。③依据静力荷载试验的实测数据,提出采用知系数对个别指标进行修正以更好地量化桥梁加固实际效果的方法;基于相同的思路,提出了大跨坦拱桥加固效果后评估的刚度评估指标体系。最后,将逐级套箍加固技术应用于观二嘴桥的工程实践。结合全桥的静载试验数据,检验本文提出的结合荷载试验的强度与刚度评估指标对该桥的加固效果的后评估有效性。结果表明:本文提出的加固效果后评估指标体系是可行的、有效的。
[Abstract]:The arch bridge is the main bridge type of the existing bridge in the western highway, in which the long-span arch bridge spanning the deep valley of the river occupies a large proportion. The long-span arch bridge has the tendency to bear the force of the beam bridge because of its self-importance. The research and development of reinforcement technology is always the difficulty of bridge reinforcement, which needs to be solved. It is important and urgent to construct the evaluation index system of long-span arch bridge. This paper introduces the reinforcement mechanism, design and calculation method and construction technology of long-span arch bridge strengthened with step by step collar. Combined with the static load test, the post-evaluation strength and stiffness indexes of the bridge strengthened by this technique are put forward, and verified by an engineering example. The main research contents include the transverse distribution of the load based on the W1. With increasing section, superposition force and fracture mechanics mechanism, combined with limit state design method, the design theory and method of steer-by-stage jackets for strengthening long-span arch bridge are analyzed. At the same time, it introduces the construction technology of the reinforcement technology based on the strength and stiffness of the structure before and after reinforcement and its changes. The index system of post-reinforcement effect evaluation of long-span Tan arch bridge is established: according to the change of the bearing capacity of the structure before and after reinforcement, the change of the stress of dead load, the range of change of constant load and live load, and the stress level of strengthened layer. Four indexes, I. e., the increasing rate of bearing capacity 伪 L (or 伪 L +), the rate of change of stress at dead load 伪 D, the rate of load replacement 伪 T, and the utilization ratio 伪 M of strengthened layer are proposed. On the basis of the measured data of static load test, this paper discusses the engineering significance and action of the four indexes, and puts forward a method of modifying individual indexes by using the known coefficient to better quantify the actual effect of bridge reinforcement. Based on the same idea, the stiffness evaluation index system of long-span Tan arch bridge after strengthening effect is put forward. Finally, the stepwise jacketed reinforcement technology is applied to the engineering practice of the two-mouth bridge, and the static load test data of the whole bridge are combined. The post-evaluation validity of the strength and stiffness evaluation index proposed in this paper for the reinforcement effect of the bridge is tested. The results show that the post-evaluation index system is feasible and effective.
【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】：U445.72

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