基于大件运输的圬工拱桥增大截面法提载加固研究

发布时间：2018-04-01 07:21

本文选题：大件运输　切入点：承载力　出处：《昆明理工大学》2017年硕士论文

【摘要】：大件运输在当前的公路交通运输当中扮演着越来越重要的角色。在所有公路中,大件车主要经过二、三级的低等级公路,这些公路采用较低等级的设计荷载标准,而公路圬工拱桥是各低等级道路桥梁中最主要的桥型之一。因此对于大件运输的圬工拱桥的承载力验算和评定以及加固的研究很有意义。增大截面加固法以其加固效果明显、经济效益较高、施工方便快捷的优点,在旧桥加固中的运用广泛。故本文从圬工拱桥承载力验算方法和增大截面法加固两方面进行研究,主要工作如下:首先,对桥梁的承载力评定和验算方法进行研究。考虑到大件车移动荷载对于桥梁的冲击力很大,不同车速的大件车会对桥梁产生不同的冲击力,因此大件车在过桥时车速应进行限制严格。本文从交通限速方面来研究桥梁承载力,假设了路面平整度较好,仅以车速为研究对象。结合某拱桥建立有限元模型,运用瞬态动力分析法,对大件车在不同车速下桥梁的动力响应进行分析计算,进而推算出相应的冲击系数。根据分析出来的冲击系数,总结出大件车通行桥梁时的速度限制范围,即以5km/h匀速过桥最宜,为实际公路桥梁大件运输时的交通管制提供限速参考。最终在大件车限速过桥的基础上,本文提出了以活载效应比较法为辅,实际荷载检算法为主的承载能力验算方法。其次,本文结合增大截面法加固的工程实例对旧桥加固前后进行内力、应力对比,对加固的效果进行分析,同时进行静载试验对加固后实桥的承载力加以评定,确定该桥的承载能力能够满足大件运输的要求。最后,为了进一步研究增大截面法的加固效果,考虑到增大截面法加固拱圈的位置和加固厚度两个参数对加固效果的影响很大,便分别对圬工拱桥的拱背、拱腹局部或全截面加固进行建模计算,对内力、应力值进行对比。从而总结出其加固效果和敏感性,为该方法在实际加固工程中的运用提供实用的指导和参考。
[Abstract]:Large-ticket transportation plays a more and more important role in the current highway transportation.In all highways, large vehicle owners have to pass through two or three grades of low-grade highways. These highways adopt lower design load standards, and highway masonry arch bridges are one of the most important types of low-grade road bridges.Therefore, it is of great significance to check and evaluate the bearing capacity of large-piece transport masonry arch bridge and to study the reinforcement of masonry arch bridge.The reinforcement method of increasing section is widely used in the reinforcement of old bridges because of its obvious effect, high economic benefit and convenient and quick construction.The main work of this paper is as follows: firstly, the bearing capacity evaluation and checking calculation method of the bridge are studied.Considering that the impact force of the large truck moving load on the bridge is very large, the large car with different speed will produce different impact force on the bridge, so the speed of the large truck should be restricted strictly when crossing the bridge.In this paper, the bridge bearing capacity is studied from the aspect of traffic speed limit, assuming that the pavement smoothness is better, and only the speed of the bridge is taken as the object of study.Based on the finite element model of an arch bridge and the transient dynamic analysis method, the dynamic response of a large vehicle under different speeds is analyzed and calculated, and the corresponding impact coefficient is calculated.According to the analysis of the impact coefficient, the speed limit range of the large truck passing through the bridge is summarized, that is, the 5km/h uniform speed is the most suitable for crossing the bridge, which provides the speed limit reference for the traffic control of the actual highway bridge.Finally, on the basis of the speed limit of large vehicle, this paper puts forward a method of checking load capacity, which is supplemented by the comparison method of live load effect and the actual load checking algorithm.Secondly, the paper compares the internal force and stress of the old bridge before and after strengthening, and analyzes the effect of the reinforcement, and evaluates the bearing capacity of the strengthened bridge by static load test.Determine the bearing capacity of the bridge to meet the requirements of large-load transportation.Finally, in order to further study the reinforcement effect of increasing cross-section method, considering that the location and thickness of arch ring strengthened by increasing section method have great influence on the reinforcement effect, the arch back of masonry arch bridge is separately studied.The local or full section reinforcement of arch abutment is modeled and calculated, and the internal force and stress are compared.Thus, the reinforcement effect and sensitivity are summarized, which provides practical guidance and reference for the application of this method in practical reinforcement engineering.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U445.72

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