复杂交通条件下斜拉桥部分换索控制研究

发布时间：2018-03-19 05:22

本文选题：斜拉桥　切入点：复杂交通条件　出处：《重庆交通大学》2015年硕士论文　论文类型：学位论文

【摘要】：斜拉桥在世界范围内的应用从20世纪70年代开始,通过近40年的建设和发展,使其成为了一种较常见的桥型。但经过多年运营,斜拉桥暴露的问题越来越多,其中最严重的是斜拉索的腐蚀和损坏。而斜拉索作为结构的主要受力构件,不及时进行更换或处治,将会给结构运营埋下极大的安全隐患。在换索的过程中,通常的做法是全桥封闭交通,最大限度的保证施工安全。然而,随着交通运输事业的不断发展,这种保护措施给市民出行和交通通畅带来的困扰越来越突显。特别是对于那些处于交通咽喉部位的市政斜拉桥和高速公路斜拉桥,影响尤其明显,如何在确保结构换索安全的同时、尽可能的维持交通通畅是社会各界关心的重要问题。本文以渝合高速公路沙溪庙嘉陵江大桥斜拉索火烧后换索工程为研究背景,对复杂交通条件下斜拉桥部分换索的换索方案及控制问题进行了研究,主要研究内容如下：①在开放交通状态下,车辆引起的冲击效应会对桥梁结构造成一定振动,通过对斜拉桥换索施工监控常用方法的总结,结合复杂交通条件下斜拉桥换索的特点,对各监测技术及方法在复杂交通条件下斜拉桥部分换索下的适用性进行了分析。②提出了斜拉桥换索过程中保证结构受力安全的控制条件与建议量值。换索过程中,斜拉索的安全系数宜在规范基础上根据拉索受损情况酌情提高；主梁变形除满足规范相关要求外,同时宜小于设计活载标准作用下的理论计算变形；主梁应力应满足设计规范要求,同时宜控制在正常使用状态下应力包络图内。③在桥梁处于全封闭状态的假设下,通过建立有限元空间分析模型,从不同换索顺序和不同换索数量两个角度出发,进行模拟计算,对各工况下斜拉索索力、梁应力及变形进行了分析,研究了各换索方案对斜拉桥结构的影响及其可行性。④根据交通组织方案,模拟交通开放时的车辆荷载,通过空间分析表明,合川岸下游侧斜拉索更换对“同岸异侧”和“同侧异岸”相关斜拉索的索力基本没有影响。在交通组织方案允许的荷载状态下,对换索过程中索力、主梁应力及变形的变化进行了分析,论证了换索方案和交通组织方案的可行性。⑤通过对索力、桥面线形、主梁应力、塔偏位等量值的监测,对换索施工进行了有效监控。各项监测结果表明,换索前后索力变化过程及结构内力、桥面线形均较好的满足设计预期及要求,施工监控有力支持和指导了开放交通条件下的换索工程施工,可为类似工程提供参考。
[Abstract]:Since 1970s, the cable-stayed bridge has been used in the world. After nearly 40 years of construction and development, the cable-stayed bridge has become a more common type of bridge. However, after many years of operation, more and more problems have been exposed to the cable-stayed bridge. Among them, the most serious is the corrosion and damage of the stay cables. As the main stress member of the structure, the cable will not be replaced or treated in time, which will lay a great safety hazard in the operation of the structure. In the process of changing the cable, The usual practice is to close the whole bridge to ensure construction safety to the maximum extent. However, with the continuous development of the transportation industry, This kind of protection measures have brought more and more serious problems to citizens' travel and traffic, especially for municipal cable-stayed bridges and highway cable-stayed bridges, which are located in traffic throats. How to ensure the safety of structural cable replacement while maintaining the smooth traffic as far as possible is an important issue of concern to all circles of society. This paper takes the cable replacement project of Shaxi Miao Jialing River Bridge of Yuhe Expressway as the research background. In this paper, the cable-changing scheme and control of cable-stayed bridge under complex traffic conditions are studied. The main contents are as follows: 1 under open traffic condition, the shock effect caused by vehicle will cause certain vibration to bridge structure. Through summing up the common monitoring methods of cable-stayed bridge construction, combining with the characteristics of cable-stayed bridge under complicated traffic conditions, The applicability of various monitoring techniques and methods in cable-stayed bridges under complex traffic conditions is analyzed. 2. The control conditions and recommended values for ensuring structural stress safety in cable-changing process of cable-stayed bridges are put forward. The safety factor of the cable should be improved according to the damaged condition of the cable on the basis of the code, and the deformation of the main beam should be smaller than the theoretical deformation under the action of the design live load standard in addition to meeting the relevant requirements of the code. The stress of the main beam should meet the requirements of the design code. At the same time, the stress envelope diagram should be controlled under the assumption that the bridge is in a completely closed state. The finite element spatial analysis model is established. Based on the different order of changing cables and the number of changing cables, the stress and deformation of cable-stayed cables under different working conditions are analyzed. This paper studies the influence of cable-changing schemes on cable-stayed bridge structure and its feasibility .4 according to the traffic organization scheme, the vehicle load when the traffic is open is simulated, and the spatial analysis shows that, The replacement of cable on the downstream side of Hechuan bank has no effect on the cable force of "the opposite side of the same bank" and "the other side of the same side". Under the load condition permitted by the traffic organization scheme, the cable force in the process of cable exchange is not affected. The variation of stress and deformation of the main beam is analyzed, and the feasibility of the cable exchange scheme and the traffic organization scheme is demonstrated. 5 through the monitoring of the cable force, the line shape of the bridge deck, the stress of the main beam, the position of the tower, etc. The monitoring results show that the change process of cable force and the internal force of the structure before and after the cable change can meet the design expectations and requirements well. Construction monitoring can support and guide the construction of cable exchange projects under open traffic conditions, which can provide reference for similar projects.
【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】：U448.27

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