在役公路钢桁架连续梁桥剩余疲劳寿命评估

发布时间：2018-01-15 07:31

本文关键词：在役公路钢桁架连续梁桥剩余疲劳寿命评估　出处：《重庆交通大学》2014年硕士论文　论文类型：学位论文

【摘要】：我国很多在役钢桁架桥梁的运营时间超过了50年,交通荷载的增加,加速了桥梁桁架结构内部的疲劳损伤,这些桥梁易发生疲劳破坏,并且疲劳破坏常导致的桥梁结构的断裂倒塌,具有突发性。为了消除在役钢桁架桥梁的疲劳隐患,科学评断对桥梁的维修与更换提供科学的评断,研究在役钢桁架桥梁的剩余疲劳寿命评估的方法流程是至关重要的。论文搜集总结了国内外钢结构剩余疲劳寿命的文献与研究成果,结合嘉陵江牛角沱大桥安全性评估项目,对在役钢桁架连续梁桥的的结构受力状态、桁架构件的疲劳性能、城市公路梁桥的应力谱的模拟方法,进行了一定的研究,建立了适合在役公路钢桁架连续梁桥剩余寿命评估的方法。论文主要进行了以下几点研究工作： ①采用梁单元建立钢桁架空间有限元模型,根据嘉陵江牛角沱大桥的设计图纸和现场考察,合理释放梁端约束。 ②通过桥梁结构模型分析,选取桁架梁桥的疲劳控制杆件。 ③截取替换桁架梁桥的典型杆件。 ④加工制作材料性能和疲劳性能试验杆件。 ⑤在现场调查梁桥交通荷载的基础上,用分时段内统计的桥梁的车辆数控制车辆的车间距,模拟梁桥的交通荷载和桁架杆件的应力谱。 ⑥用名义应力法,对嘉陵江牛角沱大桥的剩余寿命进行了评估。本文主要通过典型杆件的全截面疲劳加载试验和实测与模拟关键杆件的应力时程对钢桥的疲劳性能进行评估。在进行关键杆件选取时,主要考虑两个因素,即杆件的活载应力幅较大、杆件的平均应力较小。由于依托工程为铆接钢桥,并且所选取的典型杆件共由四个不等边角钢组成,构件上下两端采用铆钉和钢桁架节点板连接,角钢之间通过缀板进行连接,缀板与角钢间均为铆钉铆合；角钢与节点板件间为热铆工艺,不宜拆除,故选择典型构件中一肢截取部分角钢进行试验。通过分别进行典型杆件的疲劳性能评估和整个桥梁控制杆件的剩余疲劳寿命计算,得出了嘉陵江牛角沱大桥结构中杆件最短的剩余疲劳寿命为46.82年。嘉陵江牛角沱大桥的剩余疲劳寿命评估流程对同类钢桥的剩余疲劳寿命的评估具有一定的参考意义。
[Abstract]:Many of our existing steel truss bridge operation for more than 50 years, the increase of traffic load, accelerated the fatigue damage of internal bridge truss structure, these bridges are prone to fatigue failure, fatigue failure and fracture often leads to the collapse of the bridge structure, with a sudden. To eliminate fatigue problems of steel truss bridges in service the scientific judgment of the bridge maintenance and replacement to provide scientific judgment, process study assessment method of residual fatigue life of existing steel truss bridge is very important.
The paper summarizes the literature and research results of the residual fatigue life of steel structure at home and abroad, combined with the Jialing River Niujiaotuo bridge safety assessment project, the stress structure of continuous beam bridge in service steel truss, the fatigue performance of truss members, should the city force spectrum simulation method of highway beam bridge, the the study, to establish a suitable evaluation method of remaining life in the service of highway steel truss continuous girder bridge.
The main research work of this paper is as follows:
(1) the finite element model of steel truss is set up by beam element, and the beam end constraint is reasonably released according to the design drawings and field investigation of the Jialingjiang Niu jio Tuo bridge.
Secondly, through the analysis of the bridge structure model, the fatigue control rods of the truss girder bridge are selected.
3. Truncate the typical member of the replacement truss bridge.
(4) processing and making material performance and fatigue performance test rod.
(5) on the basis of on-site investigation of traffic load on beam bridges, we use the number of vehicles that are counted in time intervals to control the vehicle spacing, and simulate the traffic load and the stress spectrum of truss members.
The nominal stress method, the residual life of the Jialing River Niujiaotuo bridge is evaluated.
This paper evaluated mainly through the whole section of fatigue testing and measurement of typical members and key members of the simulation of the stress time history of fatigue performance of steel bridge. The key member selection, consider two main factors, namely the bar of the live load stress amplitude is larger, the average stress of small bar. Because the project is a typical member of riveted steel bridges, and selected a total of four equilateral angle steel member, the upper and lower ends of the rivet and the steel truss plate connection, angle between connected by batten plate, batten plate and angle between rivet riveting; angle and node plate element for heat the riveting process, should not be removed, so the choice of a limb interception of some typical components in angle test.
Through the fatigue performance evaluation of typical rods and the remaining fatigue life calculation of the whole bridge control rod, it is concluded that the shortest residual fatigue life of the bar in the Jialing River Niu Jiao Tuo bridge is 46.82 years.
The residual fatigue life assessment process of the Jialingjiang Niu jio Tuo bridge is of certain reference significance for the assessment of the remaining fatigue life of the same kind of steel bridge.

【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U441.4

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