【作者】 满洪高；

【导师】 李乔；

【作者基本信息】 西南交通大学 ， 桥梁与隧道工程， 2007， 博士

【摘要】 随着大跨斜拉桥的不断发展，对其索梁锚固结构也提出了更高的要求。索梁锚固结构区域受力集中、构造复杂，是控制设计的关键部位，掌握索梁锚固结构的应力分布情况和疲劳性能是十分重要的。本文介绍了大跨度钢箱梁斜拉桥索梁锚固结构常见的4种连接形式：锚箱式、耳板式、锚管式和锚拉板式连接，并对安庆长江大桥和苏通长江公路大桥锚箱式索梁锚固结构进行了足尺静载和疲劳模型试验。围绕试验，对相关问题展开了分析和理论研究，论文主要内容如下：1．对索梁锚固结构相关的一些试验和理论研究进行了介绍，对各种索梁锚固结构的传力途径、应力分布、应力集中现象进行了分析。2．利用空间有限元法对索梁锚固结构进行非线性仿真分析，采用不同方法建模，并将计算结果与静载模型试验结果相比较，验证了实体单元加接触单元法的计算模型能够较真实地反映锚箱锚垫板与承压板之间不焊接但紧密压贴的关系。3．由于目前软硬件能力的限制，在进行大跨度斜拉桥钢锚箱式索梁锚固结构空间非线性仿真分析和试验时，只能采用局部模型进行研究，详细探讨了索梁锚固结构周围边界条件的不同对结构受力的影响，计算了实桥模型在不同约束条件下索梁锚固区的各种应力分布情况。4．针对我国公路桥梁设计规范暂无疲劳荷载规定的情况，在综合国内一些城市和国道路段车辆荷载统计资料的基础上，参照苏通长江大桥工可交通量的预测和公路工程技术标准，确定了能够引起大桥疲劳的车重及其数量，进而计算了等效标准疲劳加载车重量及其作用在不同车道引起的索力变化，最后参考国外规范和研究成果，根据疲劳累积损伤理论，对苏通长江公路大桥主桥索梁锚固结构疲劳试验荷载的计算公式、方法进行了研究。5．为了避免出现斜拉桥索梁锚固结构疲劳试验中辅助部分首先疲劳开裂的问题，在以往索梁锚固结构疲劳试验模型设计的基础上，考虑结构疲劳寿命的影响因素，研究了疲劳试验模型设计的进一步优化，结合苏通长江公路大桥钢锚箱式索梁锚固结构足尺疲劳试验，验证了锚箱式索梁锚固结构的疲劳可靠性。6．在试验和理论计算的基础上，得出了索力在锚箱式索梁锚固区主要焊缝间的分配比例，分析了锚固区主要板件的受力特点和产生应力集中的原因；探讨了索梁锚固结构的设计优化，研究了主要焊缝长度、加劲肋和横隔板等对主梁腹板应力的影响。提出了一些可供参考的优化设计原则。更多还原

【Abstract】 With the development of long-span cable-stayed bridge, the cable-girder anchorage structure of the bridge is put forward a higher request. The cable-girder anchorage zones of cable-stayed bridges which bear giant cable forces and have complicated structure, are keys to structure design. It is very important to know the strength and fatigue property of the cable-girder anchorage structure. Several typical models of cable-girder anchorage for long-span cable-stayed bridges with steel box girder, such as anchor-box, auricular anchor plate, anchor-pipe, tensile anchor plate, are described in this thesis. Under the background of Anqing Yangtze River Bridge and Suzhou-nantong Yangtze River Bridge, full scale static load model test and fatigue test of the cable-girder anchorage zone have been carried out. Based on the model tests, large quantity of imitate calculations and theoretical analysis for the correlative problems have been done. The content of this dissertation is as follows:1. A few of tests and thesis reasech about the cable-girder anchorage structure have been described, the force transmission route, stress distribution and stress concentration under the condition of dead load to cable-girder anchorage structure have been studied, and some beneficial results are obtained.2. To study the cable-girder anchorage for long-span cable-stayed bridge, 3D nonlinear finite element models have been established by different methods. The results of model tests are compared with 3D finite element analysis. And the comparison shows the reliability of the method which solid element with nonlinear contact element simulating the state that the anchorage frame and the setting plate are not welded together but only pressed closely to each other.3. With the limitation of practical software and hardware, only the local-zone model can be adopted to analyze in 3D nonlinear analysis and model test to steel-anchor-box at the cable-girder anchorage zone for long-span cable-stayed bridge. And the results of analysis are influenced by the finite-element models’ size and boundary condition. The results of model tests are compared with 3D finite element analysis. The problems of the affection of boundary conditions to the stress in the real structure and the mechanical behavior in the cable-girder anchorage are studied. 4. To counter the situation that there is no rules about fatigue loads in China highway bridge design codes, Based on the survey of the traffic conditions of some domestic urban roads and a few of national highways, consult of the feasible traffic volume forecast for Suzhou-nantong Yangtze: River Bridge and Chinese highway construction technical standard, the fatigue load has been set up firstly, then, the variety of cable force has been calculated voider different lane load. The calculation method and formula of highway bridge fatigue loads have been given. Some abroad design codes and the theory of cumulative damage for fatigue have been used in the research.5. To avoid the accessorial structure destroyed firstly in fatigue test model for the cable-girder anchorage zone of steel cable-stayed bridges. Based on a few of former fatigue test designs for the cable-girder anchorage zone, various factors affecting the fatigue life are introduced, and structural multi-objective optimum design has been described. With the background of Suzhou-nantong Yangtze River Bridge, full scale static and fatigue model test of the cable-girder anchorage zone has been carried out. The results of model tests verified correctness of its design.6. Based on the model tests and large quantity of theoretical calculations, the quantificational description of the cable force distribution has been given in the principal welding lines of the box-shaped anchorage zone. The mechanical characteristics of the main plates and the cause of stress concentration have been studied. For further optimization design, the influences of weld length , stiffening rib and diaphragm plate for the web stresses distribution are studied and compared. Some useful principles have been disscussed, and it is beneficial to the design of bridges.更多还原