自锚式悬索桥的荷载试验与结构受力性能分析

发布时间：2018-07-26 07:26

【摘要】：为了保证现有自锚式悬索桥的安全运营,尽可能延长桥梁的安全使用年限,需要对自锚式悬索桥进行检测评估,了解它的安全状况和剩余承载力。本文以小龙湾桥为工程背景,分析混凝土自锚式悬索桥的受力性能。本文采用非线性杆系有限元法对自锚式悬索桥进行受力性能的分析。通过荷载试验对小龙湾桥的进行承载能力的评定。首先通过外观评估检测法检测小龙湾桥的各个重要部件,对正常使用状况下的小龙湾桥进行结构状况的评估,鉴定小龙湾桥的等级。再施加不同类型的车辆荷载,研究主缆位移、主塔塔顶位移、塔顶截面应力、主缆锚跨内力和主梁截面应力分布的规律。之后运用Midas/Civil软件建立三维空间杆系模型,进行等效的荷载试验模拟。借助等效杆系模型研究不同结构刚度参数对自锚式悬索桥主梁的受力特性和桥梁整体振动频率的影响。研究表明:对于自锚式悬索桥,主梁刚度对结构总体刚度的影响比较大,增加主梁刚度可以明显减少主梁受到的弯矩作用,因此在自锚式悬索桥的设计中可以适当增加加劲梁的梁高。同时主梁刚度和主缆刚度对自锚式悬索桥的振动频率有很大的影响,增大主梁刚度或主缆刚度都会提高自锚式悬索桥的振动频率,因此考虑到减隔震和行车舒适性,主梁刚度和主缆刚度可以适当提升。本文主要是对自锚式悬索桥的静载试验以及动载试验中的振动特性方面进行的研究,对于行车动力响应并没有进行深入的研究,具有一定的局限性。但是通过静载试验与振动特性的研究已经可以较好地反应出自锚式悬索桥的安全性和承载能力,因此本文的研究可以给同类型桥梁的研究一些参考。
[Abstract]:In order to ensure the safe operation of the existing self-anchored suspension bridge and prolong the safety service life of the bridge, it is necessary to test and evaluate the self-anchored suspension bridge to understand its safety status and residual bearing capacity. Taking Xiaolong Bay Bridge as the engineering background, this paper analyzes the mechanical behavior of concrete self-anchored suspension bridge. In this paper, nonlinear finite element method is used to analyze the mechanical behavior of self-anchored suspension bridge. The loading capacity of Xiaolong Bay Bridge is evaluated by load test. At first, the main components of Xiaolong Bay Bridge are detected by appearance evaluation method, and the structure of Xiaolong Bay Bridge in normal use is evaluated to identify the grade of Xiaolong Bay Bridge. The displacement of the main cable, the displacement of the top of the main tower, the stress of the top section of the tower, the internal force of the anchor span of the main cable and the stress distribution of the cross section of the main beam are studied by applying different types of vehicle loads. Then the three-dimensional spatial bar model is established by Midas/Civil software, and the equivalent load test simulation is carried out. The effects of different structural stiffness parameters on the stress characteristics of the main girder and the overall vibration frequency of the self-anchored suspension bridge are studied by using the equivalent bar system model. The results show that for self-anchored suspension bridge, the stiffness of the main beam has a great effect on the overall stiffness of the structure, and the increase of the stiffness of the main beam can obviously reduce the moment effect of the main beam. Therefore, in the design of self-anchored suspension bridge, the beam height of stiffened beam can be increased appropriately. At the same time, the stiffness of the main beam and the main cable have great influence on the vibration frequency of the self-anchored suspension bridge. Increasing the stiffness of the main beam or the main cable will increase the vibration frequency of the self-anchored suspension bridge. The stiffness of the main beam and the main cable can be raised appropriately. In this paper, the static load test of self-anchored suspension bridge and the vibration characteristics of the dynamic load test are studied, but there is no in-depth study on the dynamic response of the vehicle, which has some limitations. However, the study of static load test and vibration characteristics can reflect the safety and bearing capacity of the anchor suspension bridge, so the research in this paper can be used as a reference for the study of the same type of bridge.
【学位授予单位】：南京理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U448.25

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