预应力混凝土斜拉桥施工监控及健康监测若干问题研究

发布时间：2018-03-16 03:14

本文选题：混凝土斜拉桥　切入点：施工监控　出处：《浙江大学》2014年硕士论文　论文类型：学位论文

【摘要】：斜拉桥以其优秀的跨越能力,合理的受力体系以及新颖美观的结构形式,已经成为现代桥梁结构中发展最快,最具有竞争力的桥型之一。随着斜拉桥跨度、构造复杂性和施工难度的增大,愈发要求更加完善的斜拉桥施工监控体系和健康监测系统。一方面施工监测与控制是保证大型桥梁建设质量的重要措施,在施工过程中需要对关键技术进行严格控制,及时识别、修正误差,保证成桥内力和线形与设计相符；另一方面,桥梁结构运营过程中在超载车辆和环境侵蚀等因素的影响下,将不可避免地出现各种损伤和病害,而利用倾角仪进行桥梁动态挠度的实时在线监测不仅成本较低,而且有利于及时发现桥梁的局部损坏和承载能力下降的情况并采取措施,有效预防结构的突发性灾难。在此背景下,本文结合舟山市小干大桥的结构特点,做出以下方面的工作： 1)建立有限元分析模型,进行施工仿真计算,确定了控制重点和控制参数量,为施工监控提供理论数据；得到与合理成桥状态相对应的结构理想施工参数：主梁成桥预拱度、各节段立模标高、施工阶段斜拉索张拉力、施工阶段牵索张拉力、斜拉索无应力索长等； 2)根据牵索挂篮索力的确定原则和方法,计算了以桥梁结构和挂篮施工安全为控制条件的牵索张拉力。建立挂篮的梁单元模型,验算其在不同工况的空间应力和变形。同时针对挂篮牵索处应力集中的问题建立空间板壳单元模型,进行局部分析； 3)针对斜拉桥,采用QY型伺服式倾角仪进行桥梁转角的测量,基于三次样条曲线理论,建立了由转角计算挠度的数学模型,通过有限元仿真,检验了此模型的精度； 4)根据斜拉索索力测量精度的影响理论,考虑了牵索接长杆和减震器两个因素在不同索力测量阶段对于索力测量精度的影响；根据采样定理和工程实践确定了每根斜拉索索力测量过程中采样频率的范围。
[Abstract]:The cable-stayed bridge has become one of the fastest growing and most competitive bridge types in modern bridge structure with its excellent span ability, reasonable force system and novel and beautiful structural form, with the span of cable-stayed bridge, With the increase of structural complexity and construction difficulty, more perfect construction monitoring system and health monitoring system for cable-stayed bridges are required. On the one hand, construction monitoring and control is an important measure to ensure the construction quality of large bridges. In the process of construction, it is necessary to strictly control the key technologies, identify and correct the errors in time, and ensure that the internal force and alignment of the bridge are in accordance with the design. On the other hand, under the influence of overloaded vehicles and environmental erosion during the operation of the bridge structure, All kinds of damage and diseases will inevitably occur, and the real-time on-line monitoring of bridge dynamic deflection by using dipmeter is not only low cost, but also helpful to discover the local damage and reduce the bearing capacity of the bridge in time and to take measures. In this context, combining the structural characteristics of Xiaogan Bridge in Zhoushan City, the following work has been done:. 1) establish the finite element analysis model, carry on the construction simulation calculation, determine the control emphasis and control parameter quantity, provide the theoretical data for the construction monitoring and control, obtain the ideal construction parameter of the structure corresponding to the reasonable completion state of the bridge: the pre-arch degree of the main girder bridge, The elevation of each section of the formwork, the tension of cable in construction stage, the tension of cable in construction stage, the length of cable without stress, etc. 2) according to the principle and method of determining the cable force of the cable hanging basket, the tension of the cable is calculated under the control condition of the bridge structure and the construction safety of the hanging basket, and the beam element model of the hanging basket is established. At the same time, the spatial plate and shell element model is established to solve the problem of stress concentration in the hanging basket cable, and the local analysis is carried out. 3) aiming at the cable-stayed bridge, the angle of the bridge is measured by using the QY servo tiltmeter. Based on the cubic spline curve theory, the mathematical model of calculating the deflection from the angle of rotation is established, and the accuracy of the model is tested by finite element simulation. 4) according to the theory of the influence of cable force measurement precision, the influence of two factors, the long cable connecting rod and the shock absorber, on the cable force measurement accuracy in different stages of cable force measurement is considered. According to the sampling theorem and engineering practice, the range of sampling frequency in the process of measuring the force of each cable is determined.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U448.27;U446

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