预应力混凝土箱梁桥腹板竖向预应力检测技术研究
发布时间：2019-06-10 04:56
【摘要】：预应力混凝土连续（刚构）箱梁桥在近几十年来以其结构刚度大、行车平顺舒适、养护简单和施工方法成熟且易为工程单位掌握等一系列优势而发展迅速。但在已建成的桥梁中,有相当数量的预应力混凝土箱梁桥在施工过程中或使用过程中出现一系列桥梁病害；桥梁病害中尤以箱梁腹板斜裂缝的产生和发展较为普遍，腹板斜裂缝直接危及桥梁的耐久性和安全性。竖向预应力损失过大或失效是导致混凝土箱梁桥腹板开裂的主要原因之一；因此采用一种方便、有效的检测方法控制竖向预应力筋的有效应力，是改善竖向预应力筋的张拉质量防止腹板开裂的一个重要措施。本文以振动测试法为重点研究内容，并应用振动测试法在桥梁现场对预应力筋张拉质量进行控制，取得了一些研究成果，所进行的研究工作及成果如下： 首先，基于接触刚度的概念，分离正比接触应力，建立多种分析模型，比较其对锚垫板倾斜角的敏感程度。在室内模型和多座箱梁桥现场k-T关系曲线标定试验中，验证了锚垫板不同程度的倾斜度影响特征系数k值，，加工倾斜度为0°、1°、2°、3°、4°五种锚垫板进行室内试验，以定量确定倾斜度对k值影响程度，提出对锚垫板倾斜角的修正方法。其次，研究特征系数与张拉力关系曲线试验方法，为标定试验预应力筋中有效力的计算提供理论依据；通过室内模型试验验证标定试验方法的可靠性和稳定性。最后，应用竖向预应力筋张拉力振动测试方法测试了多座桥梁的竖向预应力筋张拉力，获得反映竖向预应力张拉质量现状的定量评估数据，有效地消除了人为因素，测试数据表明张拉质量有明显提高，证明了振动测试方法的可靠性。拟定了相应检测流程和合格标准，以有效保证预应力筋的张拉质量。
[Abstract]:In recent decades, prestressed concrete continuous (rigid frame) box girder bridge has developed rapidly because of its large structural stiffness, smooth and comfortable driving, simple maintenance and mature construction method, which is easy to be mastered by engineering units. However, in the built bridges, a considerable number of prestressed concrete box girder bridges appear a series of bridge diseases in the construction process or in the process of use. The occurrence and development of oblique cracks in the web of box girder are more common in bridge diseases, and the oblique cracks in webs directly endanger the durability and safety of bridges. Excessive loss or failure of vertical prestress is one of the main causes of web cracking of concrete box girder bridge. Therefore, it is an important measure to improve the tensile quality of vertical prestress tendons to prevent web cracking by using a convenient and effective detection method to control the effective stress of vertical prestressed tendons. In this paper, the vibration test method is taken as the research content, and the vibration test method is used to control the tensile quality of prestressed tendons in the bridge site, and some research results are obtained. The research work and results are as follows: first, Based on the concept of contact stiffness, the proportional contact stress is separated, and a variety of analytical models are established to compare the sensitivity of the contact stiffness to the inclination angle of the anchor gasket. In the indoor model and the calibration test of k 鈮
本文编号：2496186
[Abstract]:In recent decades, prestressed concrete continuous (rigid frame) box girder bridge has developed rapidly because of its large structural stiffness, smooth and comfortable driving, simple maintenance and mature construction method, which is easy to be mastered by engineering units. However, in the built bridges, a considerable number of prestressed concrete box girder bridges appear a series of bridge diseases in the construction process or in the process of use. The occurrence and development of oblique cracks in the web of box girder are more common in bridge diseases, and the oblique cracks in webs directly endanger the durability and safety of bridges. Excessive loss or failure of vertical prestress is one of the main causes of web cracking of concrete box girder bridge. Therefore, it is an important measure to improve the tensile quality of vertical prestress tendons to prevent web cracking by using a convenient and effective detection method to control the effective stress of vertical prestressed tendons. In this paper, the vibration test method is taken as the research content, and the vibration test method is used to control the tensile quality of prestressed tendons in the bridge site, and some research results are obtained. The research work and results are as follows: first, Based on the concept of contact stiffness, the proportional contact stress is separated, and a variety of analytical models are established to compare the sensitivity of the contact stiffness to the inclination angle of the anchor gasket. In the indoor model and the calibration test of k 鈮
本文编号：2496186
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