混凝土桥塔既有竖向裂缝温变特性研究

发布时间：2018-05-21 11:13

本文选题：混凝土桥塔 + 竖向裂缝　；参考：《长安大学》2015年硕士论文

【摘要】：近些年来斜拉桥、悬索桥混凝土桥塔在使用过程中出现了很多裂缝,这些裂缝主要为竖向裂缝。经初步判断,在诸多引起混凝土桥塔产生竖向裂缝的因素中,温变效应是一个重要的影响因素。国内外学者在混凝土桥梁上部结构裂缝与温变效应方面做了大量的研究工作,提出了一系列有关混凝土结构裂缝和温度应力的计算方法,但是在混凝土桥塔竖向裂缝与温变效应方面的研究还没有一套完整的理论供实际工程参考,仍存在需要进一步研究的内容。本文通过对某一混凝土桥塔温度场和裂缝变化进行实际观测并建立有限元模型,对混凝土桥塔的温度场分布、应力场分布、裂缝分布形态及其影响因素和防裂修复措施进行了详细的研究。主要内容包括:1、论述了国内外混凝土桥梁温度场分布、温度应力及裂缝的研究现状,提出了研究中存在的不足之处,归纳总结了国内外混凝土结构温变效应和断裂力学相关理论。2、以某一混凝土桥塔作为研究对象,观测了冬春两季混凝土桥塔的温度场分布情况及裂缝宽度随温度变化的扩展闭合状态,对温度场随时间的变化情况进行了分析。3、建立了桥塔实体模型,对桥塔结构沿高度方向和截面长宽方向的应力分布情况进行了计算分析,验证了温变效应是引起混凝土桥塔产生竖向裂缝的重要因素这一判断。4、基于混凝土结构断裂力学和温变效应理论,结合桥塔竖向裂缝的观测数据建立存在竖向裂缝的混凝土桥塔节段模型,对裂缝在不同温差荷载工况下的宽度变化进行计算分析。分析总结了温变条件下竖向裂缝宽度值变化情况。5、分析了除温变效应以外,引起混凝土桥塔产生竖向裂缝的原因并从设计、施工两个阶段出发提供了相应的裂缝控制措施。最后根据裂缝不同的开裂程度,提供了相应的修复方法。
[Abstract]:In recent years, there are many cracks in the concrete tower of suspension bridge, which are mainly vertical cracks. It is preliminarily judged that among the factors causing vertical cracks in concrete bridge towers, temperature variation is an important factor. Scholars at home and abroad have done a lot of research on crack and temperature variation effect of superstructure of concrete bridge, and put forward a series of calculation methods about crack and temperature stress of concrete structure. However, the research on vertical crack and temperature variation of concrete bridge tower is not a complete theory for practical engineering reference, there is still need for further research content. By observing the temperature field and crack change of a concrete bridge tower and establishing the finite element model, the distribution of temperature field and stress field of concrete bridge tower is studied in this paper. The distribution of cracks and its influencing factors and anti-crack repair measures were studied in detail. The main contents include: 1. The research status of temperature field distribution, temperature stress and crack of concrete bridges at home and abroad are discussed, and the shortcomings of the research are put forward. The related theories of temperature variation and fracture mechanics of concrete structures at home and abroad are summarized. A concrete bridge tower is taken as the research object. The distribution of temperature field and the propagation and closing state of crack width with temperature are observed. The variation of temperature field with time is analyzed, and the solid model of bridge tower is established. The stress distribution of the tower structure along the direction of height and length and width of section is calculated and analyzed. Based on the theory of fracture mechanics and temperature variation effect of concrete structure, the conclusion that temperature variation effect is an important factor causing vertical crack in concrete bridge tower is verified. Based on the observation data of vertical cracks of bridge tower, the section model of concrete tower with vertical cracks is established, and the width variation of cracks under different temperature difference load conditions is calculated and analyzed. In this paper, the variation of vertical crack width under the condition of temperature variation is summarized. Besides the temperature variation effect, the causes of vertical crack in concrete bridge tower are analyzed, and the corresponding crack control measures are provided from the two stages of design and construction. Finally, according to the different crack degree, the corresponding repair method is provided.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U441;U443.38

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