斜拉桥索塔锚固区局部应力分析

发布时间：2018-02-09 06:15

本文关键词： 斜拉桥索塔锚固区 U型预应力筋地震作用　出处：《兰州交通大学》2017年硕士论文　论文类型：学位论文

【摘要】：斜拉桥索塔拉索锚固区是将拉索巨大集中力传递给索塔的重要部位,为了承受这巨大集中力,混凝土塔柱箱壁需要布设水平预应力筋。对于索塔拉索锚固区,由于拉索孔道和预应力筋孔道的削弱作用,以及预应力筋预压力,导致该部位受力非常复杂。目前对索塔锚固区国内外没有现成的规范来进行指导设计。现阶段对斜拉桥索塔锚固区都会通过计算机有限元软件做局部分析研究,了解索塔锚固区实际工作状态下空间应力分布情况,从而为该桥设计和施工提供依据。所以斜拉桥索塔锚固区应力分析一直是桥梁研究领域的重点。该文以天水藉河大桥为工程依托。论文研究有以下必要性:对该桥索塔锚固区建立ANSYS有限元软件模型分析后发现原设计预应力筋布设不合理;该桥索塔锚固区内两侧锚固齿块是非对称设计,值得研究分析应力分布情况;目前地震作用对斜拉桥索塔锚固区的影响分析研究较少。该文将利用现阶段实际理论和有限元分析技术为基础对藉河大桥索塔锚固区做了以下研究内容:(1)对预应力混凝土结构的预应力筋应力损失理论分析,了解预应力损失原理。对预应力混凝土结构的锚固区破坏机理分析,给锚固区的局部配筋提供参考价值。(2)建立索塔锚固区有限元模型,对索塔锚固区预应力筋#字型布置和U型布置分析,得到了适合该桥的锚固区预应力筋的布置方式并验证了合理性。(3)在只有预应力作用下、成桥索力作用下和正常运营状态下分析了索塔锚固区应力变化情况以及验证了索塔锚固区的安全性能。(4)对索塔锚固区施加地震作用力后分析锚固区应力分布状态,同时与之前三种工况下的锚固区应力变化情况做了对比分析。(5)对索塔最不利拉索索孔截取水平面,取特征点分析索塔塔壁外侧和内侧边缘在四种工况作用下应力的变化情况,了解了索塔外侧和内侧边缘在顺桥向和横桥向应力分布情况。
[Abstract]:The cable cable anchoring area of cable-stayed bridge is an important part of transferring the huge concentrated force of cable to the cable tower. In order to bear this huge concentration force, the concrete tower box wall needs to be equipped with horizontal prestressed tendons. Because of the weakening effect of cable channel and prestressed reinforcement channel, as well as the prestress of prestressed tendons, At present, there are no ready-made codes to guide the design of cable tower anchoring zone at home and abroad. At this stage, the cable tower Anchorage zone of cable-stayed bridge will be studied locally by computer finite element software. To understand the spatial stress distribution in the actual working state of the cable tower Anchorage area, Therefore, stress analysis of cable tower Anchorage area of cable-stayed bridge has always been the focus of bridge research. This paper is based on Tianshui River Bridge. The necessity of this paper is as follows:. After analyzing the ANSYS finite element software model in the anchoring area of the bridge tower, it is found that the original design of prestressing tendons is not reasonable. The anchoring tooth blocks on both sides of the cable tower Anchorage area of the bridge are unsymmetrical, so it is worth studying and analyzing the stress distribution. At present, the influence of seismic action on cable tower Anchorage area of cable-stayed bridge is less studied. Based on the actual theory and finite element analysis technique at present, this paper does the following research on cable tower Anchorage area of Yuhe River Bridge: 1) prestress. Theoretical Analysis of stress loss of Prestressed tendons in Force concrete structures, To understand the principle of prestress loss, to analyze the failure mechanism of anchoring zone of prestressed concrete structure, to provide reference value for local reinforcement in anchoring area, and to establish finite element model of cable tower anchoring area. The layout of prestressed tendons # and U-shaped in cable tower Anchorage area is analyzed, and the layout mode of prestressed tendons in anchoring area suitable for the bridge is obtained, and the rationality of prestressing force is verified. Under the action of bridge cable force and under normal operation condition, the stress variation of cable tower Anchorage area is analyzed and the safety performance of cable tower Anchorage zone is verified. 4) the stress distribution state of cable tower Anchorage area is analyzed after applying seismic force to the cable tower Anchorage area. At the same time, the stress changes in the anchoring zone under the three previous conditions are compared and analyzed. The stress changes of the outside and the inner edge of the tower wall under four working conditions are analyzed by taking the characteristic points, which are the most disadvantageous cable hole intercepting the horizontal plane of the cable tower. The stress distribution of the lateral and medial edges of the tower in the forward and transverse direction is investigated.
【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U448.27

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