混凝土箱梁预应力缺陷效应模拟分析

发布时间：2018-04-30 10:24

本文选题：预应力缺陷 + 精细化施工　；参考：《重庆交通大学》2015年硕士论文

【摘要】：通过对预应力混凝土箱梁的预应力缺陷对桥梁结构影响的研究,为桥梁预应力施工的重要性提供理论依据,同时为评价预应力缺陷的影响大小提供理论参考。具有重要的理论和现实意义以及广阔的市场前景和应用价值。本文针对预应力混凝土箱梁的预应力缺陷做出了以下研究:在文章的开始阶段研究了预应力混凝土箱梁的特点及发展情况,然后据此提出其在发展过程中出现的一些病害,并对引发病害的原因进行了分析。得出结论,预应力缺陷是引起病害的主要原因之一。所以,研究存在哪些预应力缺陷、预应力缺陷产生的原因、如何控制预应力缺陷以及如何模拟分析预应力缺陷成为本文的研究方向。然后介绍了其中一种预应力缺陷—混凝土箱梁预应力不均匀。明确了预应力不均匀度的概念,提出了使用同束和同断面不均匀度来评价预应力的不均匀程度。使用数据表明在现有施工条件下预应力钢绞线锚下有效预应力的分布具有严重的非均匀性。引起我们对钢绞线锚下有效预应力均匀度的重视。然而同束或者同断面预应力不均匀度并不是唯一可以评判预应力不均匀的标准,本文提出使用各单根钢绞线锚下有效预应力的平均值-均值和各单根钢绞线锚下有效预应力偏离平均数的距离的平均数-离散程度更加能反映钢绞线锚下有效预应力的不均匀程度。在预应力损失方面,由于缺乏预应力损失与截面应力之间关系的研究,本文首次从应力的角度入手,建立有限元模型,使用模型计算并与实测数据对比,并对施工阶段某截面进行受力分析,计算得出预应力损失与截面应力之间的关系,并提出使用残余率来评价预应力损失的大小。接下来介绍了预应力精细化施工技术。这项技术是目前可以较有效控制施工过程中预应力施工病害的最好方法,在施工中具有重大的意义。主要包含内容有:锚具及其安装就位质量控制、钢束的梳编穿束工艺、预应力张拉施工以及有效预应力检测控制与智能化系统。
[Abstract]:Through the research on the influence of prestressed concrete box girder on the bridge structure, it provides the theoretical basis for the importance of the bridge prestressed construction, and also provides the theoretical reference for evaluating the influence of the prestressed concrete box girder on the bridge structure. It has important theoretical and practical significance as well as broad market prospect and application value. In this paper, the prestressing defects of prestressed concrete box girder are studied as follows: at the beginning of the article, the characteristics and development of prestressed concrete box girder are studied, and then some diseases in the process of development are put forward. The causes of disease were analyzed. It is concluded that the prestressing defect is one of the main causes of the disease. Therefore, it is the research direction of this paper to study which pre-stress defects exist, the causes of pre-stress defects, how to control the pre-stress defects and how to simulate and analyze the pre-stress defects. Then it introduces one kind of prestressing defect-the non-uniform prestress of concrete box girder. In this paper, the concept of prestress inhomogeneity is defined, and the uneven degree of prestress is evaluated by using the same beam and the same section inhomogeneity. The data show that the distribution of the effective prestress under the anchor of prestressed steel strand under the existing construction conditions has serious inhomogeneity. We attach importance to the effective prestress uniformity under the anchor of steel strand. However, the unevenness of prestress in the same bundle or section is not the only criterion to judge the uneven prestress. In this paper, it is proposed that the average value of effective prestress under each single strand anchor and the average distance between the effective prestress under each single strand anchor and the distance from the average to the average value can better reflect the effective prestressing under the steel strand anchor. The degree of inhomogeneity of the stress. In the aspect of prestress loss, due to the lack of research on the relationship between prestress loss and cross-section stress, the finite element model is established from the angle of stress for the first time, and the model is used to calculate and compare with the measured data. The relationship between prestress loss and section stress is calculated and the residual rate is used to evaluate the size of prestress loss. Then the prestress fine construction technology is introduced. This technique is the best method to control the damage of prestressing force in the construction process, and it is of great significance in construction. The main contents include: quality control of Anchorage and its installation and placement, combing and piercing process of steel strands, prestressing tensioning construction, effective prestress detection, control and intelligent system.
【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】：U445.57

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