【作者】 张茜；

【导师】 周绪红；

【作者基本信息】 长安大学 ， 桥梁与隧道工程， 2013， 博士

【摘要】 本文以青岛胶州湾大桥红岛航道桥为背景，结合山东省交通科技项目《斜拉桥索塔新型锚固体系研究》（2009Y24-2），在国、内外创新性地提出了钢锚板式钢-混组合索塔锚固体系。在收集各种钢-混组合索塔锚固体系构造形式及研究资料的基础上，采用理论分析、足尺节段模型试验的方法对钢锚板式钢-混组合索塔锚固体系的传力机理、承载能力及设计方法进行了研究。采用弹塑性有限元数值方法对钢锚板式钢-混组合索塔锚固体系在对称及单侧索力作用下的传力机理进行了研究。数值模拟采用精细化有限元模型，特别考虑了钢与混凝土间的接触非线性和摩擦力以及普通钢筋的作用。研究得到了对称及单侧索力加载全过程中斜拉索索力传递路径和钢锚板、横隔板、竖隔板、底座、侧板、混凝土、PBL剪力键分别承担的水平力和竖向力的大小与比例；同时还得到了不同位置PBL剪力键所承担的水平力和竖向力分布规律及其穿孔钢筋的有效工作长度。进行了钢锚板式钢-混组合索塔锚固体系足尺节段模型试验研究，采用与实桥相同的斜向加载方式。试验加载工况包括成桥索力工况、运营索力工况、超载工况和偏载工况，其中超载（对称加载）和偏载工况（单侧加载）均加载至2.2倍成桥恒载索力，加载至最大索力时，结构未达到其极限承载能力，表明钢锚板式钢-混组合索塔锚固体系具有较高的安全储备；对各工况加载过程中钢锚板应力和位移、混凝土应力、PBL剪力键穿孔钢筋应力进行了测试，将测试结果与有限元数值分析结果进行了对比，结果表明采用本文有限元数值方法可以较好的模拟结构的实际受力状态。对钢锚板式钢-混组合索塔锚固体系的极限承载能力进行了弹塑性有限元数值分析。得到了对称及单侧索力作用下锚固体系的极限荷载及破坏形态，同时得到了锚固体系在加载全过程中的变形、应力以及混凝土裂缝发展规律。进行了对称及单侧索力加载时锚板厚度、横隔板厚度及位置、侧板厚度、竖隔板厚度、PBL剪力键列数及其穿孔钢筋直径等参数变化对钢锚板式钢-混组合索塔锚固体系受力性能的影响分析。结果表明，锚固体系内各构件承担的水平力和竖向力以及其应力大小对锚板厚度、PBL剪力键列数的变化最为敏感；锚固体系对钢锚板厚度变化较为敏感。在上述研究成果的基础上，对钢锚板式钢-混组合索塔锚固体系构造进行了设计优化，对优化后锚固体系的受力情况及传力机理进行了数值分析。结果表明，优化后锚固体系受力安全可靠、传力更为明确，PBL建立键传递的荷载较优化前显著增大。提出了优化后钢锚板式钢-混组合索塔锚固体系的设计方法。通过分析影响PBL剪力键承载力的主要因素，提出了适用于钢锚板式钢-混组合索塔锚固体系中PBL剪力键的承载力计算公式；采用弹性理论推导了耳板销铰接触面应力的简化计算方法，可用于钢锚板厚度的设计。更多还原

【Abstract】 Based on the Hongdao Channel Bridge of Qingdao Jiaozhouwan Bridge and supported byShandong provincial transportation science-technology project of Research on the New Typeof Cable-pylon Anchorage System of Cable-stayed Bridge(2009Y24-2), steel-concretecomposite anchorage system with steel anchor slab was introduced domestically and overseasin this paper creatively. On the basis of collecting structural form and research data ofdifferent types of steel-concrete composite anchorage system, the load-transfer mechanism,load-bearing capacity and design method of this new cable-pylon anchorage system werestudied through the approaches of theoretical analysis and full-scale test.Elastic-plastic finite element numerical analysis was adopted to research load-transfermechanism of the anchorage system under symmetrical and unilateral cable force. Thenumerical simulation with a refined finite element model took the nonlinear contact andfriction between steel slab and concrete and the effect of the reinforcement into consideration.Through this research the load-transfer path of stayed-cable force and the horizontal andvertical force supported by steel anchor slab, diaphragms, vertical diaphragm, base plate,lateral plate, concrete and PBL shear connectors under symmetrical and unilateral cable forcewere found out. Besides, the transferring patterns of horizontal and vertical force of PBLshear connectors in different locations and the effective length of perforated steel wereobtained.The full scale test of steel-concrete composite anchorage system with steel anchor slabadopting the loading method which was the same as the loading method of real bridge wascarried out. The loading operating mode of the test included the cable force of finished bridgestate, operation state, overload state and partial loading state. The structure did not reach itslimit load-bearing capacity under the maximum cable force of the overload state(symmetricalloading) and partial loading state (unilateral loading)which were2.2times as large as thecable force of finished bridge state. It indicates that the anchorage system existed with ahigher safety stock. The test of the stress and displacement of steel anchor slab, the stress ofconcrete and perforated rebar under different loading operating mode were carried out. Bycomparing the results of the test and the numerical analysis, the result demonstrates that theresult obtained from the numerical simulation method adopted by this paper reflects the realstress state of the structure.The limit load and failure mode under symmetrical and unilateral cable force wereobtained by the elastic-plastic finite element analysis of limit load-bearing capacity of thisanchorage system. The deformation and stress of the anchorage system and the pattern ofcrack propagation in concrete were also get.The influence on the stress performance of steel-concrete composite anchorage systemwith steel anchor slab produced by the variation of the thickness of anchor slab, the thicknessand location of diaphragms, the thickness of vertical diaphragm and lateral plate, the numberof columns of PBL shear connectors and diameter of the perforated steel was studied. Theresult shows that the thickness of anchor slab and the number of columns of PBL shearconnectors have the most effect on the stress of every component of the anchorage system aswell as the proportion of the horizontal and vertical force supported by them. And theanchorage system is more sensitive to the variation of the thickness of steel anchor slab. Based on the research above, the construction of steel-concrete composite anchoragesystem with steel anchor slab was optimized. Numerical analysis of the optimized anchoragesystem was carried out to study the working condition and load-transfer mechanism. Theresult demonstrates that the optimized anchorage system is safety under design load, and theload transfer is more limpid, the load transferred by PBL shear connectors increasessignificantly. the design method of optimized steel-concrete composite anchorage system withsteel anchor slab were put forward. By studying the main factors that influenced theload-bearing capacity of PBL shear connectors, the calculation formula of the load-bearingcapacity of PBL shear connectors in the anchorage system was proposed. Simplifiedcalculation method of the contact stress of the pin hinge located in the wing slab was alsodeduced on the basis of the elastic theory, which could be applied to the design of thethickness of steel anchor slab.更多还原