预应力砼桁架T构病害机理分析及维修加固

发布时间：2018-01-20 12:50

本文关键词： 斜拉桁架T构桥受力特性病害机理正交试验维修加固　出处：《长安大学》2014年硕士论文　论文类型：学位论文

【摘要】：预应力混凝土斜拉桁架T构桥是一种新颖的桥梁结构，，由斜拉结构、桁架结构及T形刚构组合而成。此类型桥梁上弦杆的竖直分力支撑下弦杆，形成弹性支撑连续梁，上弦杆水平分力对下弦杆形成加劲作用，受力与斜拉桥相似；杆件的轴力均大于弯矩，其构件表现出明显的二力杆受力特性，轴力控制设计，受力与桁架桥相似；自重与预应力产生的效应最大，其他荷载效应较小，表现出连续刚构的受力特性。其自重轻、刚度大、受力明确、外观优美，但此类桥型跨中设置的剪力铰及边跨设置的拉压支座时常破坏，影响桥梁结构的安全和使用。因此，研究该类桥梁的病害机理及维修加固方案具有重要意义。主要研究内容有：（1）本文以福建省洪塘大桥为研究对象，通过建立有限元模型对预应力混凝土斜拉桁架T构桥的主要受力构件，包括上弦杆、下弦杆、腹杆、T纵梁及V型墩，进行力学特性分析，总结出构件在不同荷载工况下的内力、应力及位移的变化规律。（2）利用现场勘察报告，针对引起预应力混凝土斜拉桁架桥T构桥病害的因素进行理论分析和敏感性分析，并通过正交试验设计分析多因素组合情况下的病害机理，利用SPSS软件计算正交表，提出敏感性参数重要性排序。（3）综合预应力混凝土斜拉桁架桥T构桥病害机理和参数敏感性分析，初步编制出洪塘大桥维修加固方案，可供有关部门参考。
[Abstract]:Prestressed concrete cable-stayed truss T-frame bridge is a novel bridge structure, composed of cable-stayed structure, truss structure and T-shaped rigid frame. A continuous beam with elastic support is formed, and the horizontal force of the upper chord stiffens the lower chord, and the force is similar to that of the cable-stayed bridge. The axial force of the members is greater than the bending moment, and its members show obvious force characteristics of the two-force rod. The axial force control design is similar to that of the truss bridge. The effect of deadweight and prestress is the largest, and the other load effect is small, which shows the mechanical characteristics of continuous rigid frame. Its weight is light, its stiffness is large, the force is clear and its appearance is beautiful. However, the shear hinge in the middle of the bridge type and the tension and compression bearing in the side span are often destroyed, which affects the safety and use of the bridge structure. It is of great significance to study the disease mechanism and maintenance and reinforcement scheme of this kind of bridge. The main research contents are as follows: This paper takes the Hongtang Bridge in Fujian Province as the research object and establishes the finite element model for the main force components of the prestressed concrete cable-stayed truss T-bridge, including the upper chord, the lower chord, and the web bar. The mechanical properties of T-longitudinal beam and V-shaped pier are analyzed, and the variation of internal force, stress and displacement of members under different load conditions is summarized. 2) based on the field investigation report, the factors causing the damage of prestressed concrete cable-stayed truss bridge T-bridge are analyzed theoretically and sensitively. The disease mechanism under the condition of multi-factor combination was analyzed by orthogonal experiment design. The orthogonal table was calculated by SPSS software, and the importance ranking of sensitivity parameters was put forward. 3) based on the analysis of the damage mechanism and parameter sensitivity of prestressed concrete cable-stayed truss bridge, the maintenance and reinforcement scheme of Hongtang Bridge is worked out, which can be used as a reference for relevant departments.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U445.7;U448.231

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