【作者】 邹存俊；

【导师】 徐岳；

【作者基本信息】 长安大学 ， 桥梁与隧道工程， 2009， 博士

【摘要】 自锚式悬索—斜拉组合结构体系桥梁是一种全新的桥型,作为城市桥梁既实现了桥梁本身的使用功能,又体现了桥梁的美观和后期社会效益。但这类桥型结构复杂,传力不很明晰,国内外对其受力性能几乎未见报道。论文依托实桥工程建设需求,结合江苏省交通科学研究计划项目“自锚式悬索与斜拉组合结构体系桥梁受力性能与安全评价”(06Y19b),针对自锚式悬索—斜拉组合结构体系桥梁成桥状态与施工过程高度耦合的特点,以世界首座自锚式悬索—斜拉组合结构体系桥梁设计和施工资料收集分析为基础,以其他相似桥型理论研究成果为借鉴,以理论分析、数值计算、模型试验、实桥监控为手段,对自锚式悬索—斜拉组合结构体系桥梁施工和使用阶段的力学性能以及结构参数敏感性进行系统地研究。主要研究内容如下：(1)以应变位移协调为条件,考虑主梁和主塔的梁—柱效应,建立自锚式悬索—斜拉组合结构体系桥梁的势能泛函,根据大位移分区不完全变分原理,推导了自锚式悬索—斜拉组合结构体系桥梁的基础微分方程,建立了自锚式悬索—斜拉组合结构体系桥梁的分析理论。算例分析表明本文解析解与数值解比较接近。(2)根据结构力学理论,考虑空间交叉吊索的影响,分析自锚式悬索跨初始平衡状态,提出了自锚式悬索—斜拉组合结构体系桥梁自锚式悬索跨空间主缆线形及索力的计算方法；基于最小弯曲能量原理,考虑自锚式悬索跨对斜拉跨斜拉索力的影响,计算斜拉跨成桥状态,进而建立了自锚式悬索—斜拉组合结构体系桥梁的合理成桥状态分析计算方法。通过全桥模型试验验证计算方法的可靠性。(3)基于有限位移理论,根据悬索的精确计算公式,推导空间索单元切线刚度矩阵；根据虚功原理,推导基于U.L列式空间梁单元刚度矩阵,建立了自锚式悬索—斜拉组合结构体系桥梁结构分析的有限元计算方法；分析车辆荷载、温度荷载、温度梯度及索梁温差、收缩徐变等作用对结构内力及位移等方面的影响,得到了自锚式悬索—斜拉组合结构体系桥梁在不同荷载作用下的结构力学响应。(4)以敏感性分析理论为指导,对实桥工程的结构参数进行分析,探讨了桥跨布置(边中跨比、外伸跨长度)、主缆矢跨比、主梁预拱度、主梁刚度、缆索刚度以及主塔刚度等参数变化对结构内力和变形的影响,分析了自锚式悬索—斜拉组合结构体系桥梁的受力特性与地锚式悬索桥以及自锚式悬索桥的异同。(5)针对自锚式悬索—斜拉组合结构体系桥梁施工过程中呈现显著的几何非线性特点,考虑空间缆索、倾斜主塔、斜拉索及空间交叉吊索构成的空间效应,从结构施工过程的受力分析及施工实际出发,提出了自锚式悬索—斜拉组合结构体系桥梁空间缆索合理施工状态的分析方法；对比分析多种施工方案,提出了空间主缆空间交叉吊索自锚式悬索—斜拉组合结构体系桥梁吊索张拉技术(所有吊索只需张拉一次)。(6)以理论分析为基础,结合自锚式悬索—斜拉组合结构体系桥梁不同缆索体系张拉方案的数值分析结果,分析施工阶段的力学特性,得到了吊索张拉过程空间主缆位移变化的弱相干性,斜拉索张拉对空间主缆线形的影响,以及空间交叉吊索力的相邻影响性。以塔顶水平位移为控制原则,探讨了自锚式悬索—斜拉组合结构体系桥梁斜拉索的合理张拉时机。通过模型试验验证研究成果的正确性。(7)基于本文建立的自锚式悬索—斜拉组合结构体系桥梁合理成桥状态和合理施工状态分析方法,采用本文提出的吊索一次张拉技术,对首座自锚式悬索—斜拉组合结构体系桥梁实施施工监测和控制,通过计算与实测结果对比分析,验证了计算方法的可靠性、张拉技术的可行性和合理性。更多还原

【Abstract】 As a new type of bridge, the self-anchored suspension and cable-stayed combination system bridge embodies aesthetic effect and social benefit. But its mechanical properties are more complicated and there are few relevant papers on this kind of bridge at present. Under the background of first self-anchored suspension and cable-stayed combination system bridge in the world, this paper analyzes design and construction data, studies the mechanical properties and parameter sensitivity by use of theoretical analysis, numerical calculation, model test and safety monitoring. In detail, the following aspects are investigated:1. According to the coordination of strain and displacement, the incomplete potential energy functional of self-anchored suspension and cable-stayed combination system bridge is established based on the pressure-bending of girder and tower. The equations of this kind of bridge are approximately derived, and the analysis theory is also obtained. The example shows that the results of analytic method agree with those of numerical calculation.2. Based on the structure mechanics theory, initial equilibrium conditions on structure of self-anchored suspension is analyzed based on spatial cross suspender cable. And the calculation method of spatial line shape and suspender force on self-anchored suspension and cable-stayed combination system bridge is also proposed. Finished bridge state on structure of cable-stayed is determined according to the principle of minimum bending energy. The calculation method of reasonable finished bridge state on self-anchored suspension and cable-stayed combination system bridge is then established. Furthermore, the reliability of the method is verified by the model test.3. By using finite displacement theory and the accurate calculation formula for cable, the spatial cable element tangent stiffness matrix is deduced. The three dimensional beam element tangent stiffness matrix is also developed. Furthermore, the finite element calculation method of self-anchored suspension and cable-stayed combination system bridge is established. Mechanical responses are obtained from the load of vehicle, temperature, temperature difference, shrinkage and creep.4. Under the guidance of sensitivity analysis theory, the structure parameters of self-anchored suspension and cable-stayed combination system bridge are analyzed including the ratio between side span and main span, length of overhang span, rise-span ratio, camber of girder, beam rigidity, cable rigidity and tower rigidity. Regularities of internal force and deformation are summarized. Similarities and differences’between the self-anchored suspension and cable-stayed combination system bridge and other types of bridges are discussed.5. In view of the geometric nonlinearity on self-anchored suspension and cable-stayed combination system bridge, the analysis method of reasonable construction state is proposed according to mechanical properties and construction condition. The method involves in spatial cable, inclined tower, spatial effect of cable and cross suspender cable. Then the new tensioning technique about self-anchored suspension and cable-stayed combination system bridge is put forward.6. Mechanical properties of self-anchored suspension and cable-stayed combination system bridge in construction control are studied on the basis of difference construction method. Weak interference principle on main cable displacement and near influence principle on suspender cable force are proposed. The influence of tension of cable is studied. And the opportunity of tension of cable is also investigated to the control principle of tower displacement. These principles are proved correctly through the model test.7. For the first self-anchored suspension and cable-stayed combination system bridge, the analysis method for the finished bridge state and reasonable construction state in this paper is used. The new tensioning technique(a single tension technique) is adopted. And construction monitoring techniques for this kind of bridge are set up. By compared with calculation results and measured results, the reliability of caculation method and rationality of tensioning technique are verified.更多还原