单索面斜拉体系在大跨度连续刚构桥加固中的应用研究

发布时间：2018-04-24 15:04

本文选题：组合体系 + 单索面斜拉体系　；参考：《华南理工大学》2015年硕士论文

【摘要】：随着桥梁技术的的不断发展,大跨径预应力混凝土连续刚构桥因其具备很多优点:结构受力合理、跨越能力大、施工方便,得到了较为迅速的发展,但同时也存在很多的缺点:腹板易产生裂缝、开裂、跨中位置持续下挠,限制了其进一步的发展。本文针对大跨度连续刚构桥存在的病害问题,根据组合体系的受力特点提出了单索面塔梁组合斜拉体系加固的思路,并以佛山某大桥为工程背景,采用MIDAS/CIVIL有限元结构分析软件建立全桥的有限元模型,做了如下的研究工作。(1)以佛山某大桥为工程背景,建立其新建桥梁结构的梁单元模型,并对模型进行试算修正,得到符合实际检测结果的修正模型,即加固前连续刚构桥模型,并分别计算修正前后模型的应力值、挠度值、弯矩值等桥梁指标状况;(2)对单索面塔梁组合斜拉体系的设计参数进行分析。通过建立符合规范要求的几组不同塔高、不同中跨无索区长度、不同斜拉索布置形式的模型,在斜拉索索力相同的情况下,对比塔高、中跨无索区长度、斜拉索布置形式的变化对桥梁的应力、挠度、内力的影响大小,并确定了加固体系的设计参数的合理取值范围;(3)结合斜拉桥和连续刚构桥的合理成桥状态,提出了加固体系的合理成桥状态,即通过调整斜拉索的索力使连续刚构桥的应力状态达到最优,并约束其继续下挠。据此,提出了组合加固体系的索力计算方法,结合影响矩阵法在MIDAS/CIVIL的具体应用未知荷载系数法,确定合理成桥状态的索力,运用差值法正迭代计算出符合精度要求的斜拉索初始张拉索力;(4)以佛山某大桥为工程背景,识别加固前大跨度连续刚构桥已存应力状态、承载能力状态、挠度值,并确定出单索面斜拉体系的设计参数,分析计算加固后单索面塔梁组合斜拉体系的桥梁状况;(5)介绍了传统的体外预应力加固方法及加固原理,并与单索面斜拉体系加固方法进行各项桥梁指标对比,并分析了两种加固方法的加固效果。
[Abstract]:With the continuous development of bridge technology, long-span prestressed concrete continuous rigid frame bridge has been developed rapidly because of its many advantages: reasonable structural force, large span capacity, convenient construction. But at the same time, there are many disadvantages: the web is prone to crack, crack, continuous deflection in the middle of span, which limits its further development. Aiming at the problem of long span continuous rigid frame bridge, according to the stress characteristics of the composite system, this paper puts forward the idea of strengthening the single cable plane tower and beam composite cable-stayed system, and takes a bridge in Foshan as the engineering background. The finite element model of the whole bridge is established by using the MIDAS/CIVIL finite element structure analysis software. The following research work is done. Taking a bridge in Foshan as the engineering background, the beam element model of the new bridge structure is established, and the model is revised by trial calculation. The modified model, that is, the continuous rigid frame bridge model before reinforcement, is obtained, and the stress and deflection values of the model before and after the modification are calculated respectively. The design parameters of cable-stayed system with single cable plane tower and beam are analyzed. By establishing several groups of models of different tower height, different mid-span cable-free zone length and different cable-stayed arrangement form, in the case of the same cable force, the tower height and the mid-span no-cable zone length are compared. The influence of the cable layout on the stress, deflection and internal force of the bridge is determined, and the reasonable value range of the design parameters of the strengthened system is determined, which combines with the reasonable bridge state of the cable-stayed bridge and the continuous rigid frame bridge. In this paper, a reasonable bridge state of the reinforcement system is put forward, that is, the stress state of the continuous rigid frame bridge is optimized by adjusting the cable force of the stay cable, and the continuous deflection is restrained. Based on this, the calculation method of cable force of composite reinforcement system is put forward. Combined with the influence matrix method, the unknown load coefficient method is applied in MIDAS/CIVIL to determine the cable force in the reasonable state of the bridge. The difference method is used to calculate the initial cable tension in accordance with the precision requirement by using the difference method. Taking a bridge in Foshan as the engineering background, the existing stress state, bearing capacity state and deflection value of the long-span continuous rigid frame bridge before reinforcement are identified. The design parameters of the cable-stayed system with single cable plane are determined and the bridge condition of the composite cable-stayed system with single cable plane tower and beam after reinforcement is analyzed and calculated. (5) the traditional external prestressing strengthening method and the strengthening principle are introduced. Compared with the single cable plane cable-stayed system, the bridge indexes were compared, and the results of the two reinforcement methods were analyzed.
【学位授予单位】：华南理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U448.23;U445.72

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