桥梁后锚固节点试验研究及有限元分析

发布时间：2018-01-04 21:04

本文关键词：桥梁后锚固节点试验研究及有限元分析　出处：《沈阳工业大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着城市基础建设的日新月异的飞速发展,为了缩短工期尽快缓解交通压力将整体高架桥改为预制拼装。根据要求,将其桥梁的部分下部结构(盖梁及墩柱)改用预制拼装方案施工,而预制方案采用的是预埋波纹管的形式然后进行浇筑,在我国北方由于长期处于寒冷与温暖交替状态,常常导致钢筋锈蚀,混凝土强度下降,结构发生耐久性损坏。研究钢筋与混凝土在冻融循环作用下的粘结性能,对混凝土结构研究中的耐久性在理论和应用上具有至关重要的意义与价值。本文针对装配式桥墩后锚固节点在冻融循环作用下的的耐久性能进行了相关的试验与研究。主要有以下内容:(1)适应严寒地区冻融环境装配式桥墩后锚固节点预留孔道内压浆材料-改性砂浆的试验研究。通过该试验选择适合冻融环境的后锚固节点改性砂浆;(2)缩尺后锚固节点试件制作所需耐冻融环境的C40混凝土材料的性能试验。通过该试验确定装配式节点混凝土的材料配比,防止后续的冻融拉拔试验中出现混凝土试件首先破坏的情况;(3)后锚固节点不同冻融次数后拉拔试验。本文主要采用C40混凝土200×200×350的桥墩装配式节点缩尺试件,预埋波纹管作为钢筋预留孔道,待试件养护28天后将钢筋放入波纹管中灌入各种注浆材料,在不同冻融次数情况下对试件进行拉拔试验,分析冻融循环对后锚固节点粘接强度的影响。(4)基于abaqus有限元模拟试验分析。试验结果表明,冻融循环次数对混凝土试件以及注浆试件的相对弹性模量和抗压强度有相当大的影响;对钢筋、与预埋波纹管混凝土的粘结强度和滑移影响也比较明显,且随着冻融循环次数的增加,试件整体的粘结强度有明显的下降趋势;利用内聚力单元和CZM本构模型模拟预埋置波纹管混凝土总体上来讲有一定可行性。
[Abstract]:With the rapid development of urban infrastructure, in order to shorten the construction period and relieve traffic pressure as soon as possible, the whole viaduct will be replaced by prefabricated assembly. The partial substructure of the bridge (capping beam and pier column) is replaced by the prefabricated assembly scheme, and the prefabricated scheme adopts the form of pre-buried bellows and then pouring. In the north of China, due to the cold and warm alternating state for a long time, it often leads to the corrosion of steel bar, the decline of concrete strength, and the durability damage of structure. The bond behavior of steel bar and concrete under the action of freeze-thaw cycle is studied. It is of great significance and value in theory and application to study the durability of concrete structure. In this paper, the durability of post-anchoring joints of prefabricated bridge piers under freeze-thaw cycle is tested and tested. The main contents of the study are as follows:. (. 1) the experimental study of modified mortar, which is suitable for freezing and thawing environment, is carried out to select the modified mortar which is suitable for freezing and thawing environment. (2) performance test of C40 concrete material which needs freeze-thaw environment for the manufacture of Anchorage joints after scaling. The material ratio of prefabricated joint concrete is determined by this test. To prevent the concrete specimen from first destroying in the subsequent freeze-thaw drawing test; In this paper, the preburied corrugated pipe is used as the reserved hole of steel bar, which is composed of C40 concrete 200 脳 200 脳 350 piers. After 28 days of maintenance, the steel bar was poured into the bellows with various grouting materials, and drawing tests were carried out under different freezing and thawing times. The influence of freeze-thaw cycle on the bonding strength of post-anchoring joints is analyzed. (4) based on abaqus finite element simulation test, the experimental results show that. The number of freeze-thaw cycles has a great influence on the relative elastic modulus and compressive strength of concrete specimens and grouting specimens. The bond strength and slip of steel bar and pre-buried bellows concrete are also obvious, and with the increase of freeze-thaw cycle times, the bond strength of the whole specimen has an obvious downward trend. It is feasible to simulate embedded bellows concrete by cohesive force element and CZM constitutive model.
【学位授予单位】：沈阳工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U446

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