大跨独塔单索面混合梁斜拉桥力学性能与施工控制研究

发布时间：2018-05-21 17:34

本文选题：混合梁斜拉桥 + 钢-混结合段　；参考：《湖南大学》2014年硕士论文

【摘要】：混合梁斜拉桥边跨采用混凝土主梁，主跨采用钢主梁，两种主梁在桥塔附近通过钢-混结合段进行连接转换。混合梁斜拉桥边主跨主梁采用不同材料，同时钢-混结合段作为混合梁斜拉桥的关键部位，，其构造形式和力学特性也比较复杂，导致混合梁斜拉桥设计与施工时将面临新的问题。因此，工程技术人员和科研人员需要对混合梁斜拉桥力学性能与施工控制进行研究。混合梁斜拉桥大都采用双塔、空间索面、半漂浮体系，主跨钢箱梁在悬拼施工时通常把一个索距长度的钢箱梁作为一个节段整体进行拼装，而本文研究的斜拉桥采用的是独塔、单索面、塔梁墩固结体系，主梁在悬拼施工时，一个索距内的钢箱梁节段将分为两段先后吊装施工。大跨、独塔、单索面、宽箱等特点将使钢-混结合段在成桥运营时承受较大扭矩，主跨钢箱梁分段吊装施工将使拼装过程变得复杂。本文以云南省六库怒江二桥为工程背景，对独塔单索面混合梁斜拉桥力学性能和施工控制关键技术进行了研究，主要内容有：（1）建立怒江二桥的MIDAS有限元模型，研究其力学特点；（2）根据工程实际，研究优化施工过程及对应安装索力的方法及最优施工方案；（3）研究混合梁斜拉桥的施工控制时的关键参数，和主跨钢箱梁分段吊装的施工控制方法；（4）建立钢混结合段ANSYS有限元模型，研究其受力机理；得出的主要结论有：（1）独塔单索面混合梁斜拉桥宜采用塔梁墩固结体系；（2）独塔单索面混合梁斜拉桥钢-混结合段构造可以简化；（3）混合梁斜拉桥主跨钢箱梁悬臂吊装施工过程可用本文提出的方法优化；（4）斜拉桥施工应严格根据计算得出的无应力索长、预制线形和安装线形进行控制；（5）钢-混结合段抗扭性能良好，其中钢板承担20～30%扭矩，格式内RPC承担70～80%扭矩，（6）扭矩作用下塔梁墩固结体系的混合梁斜拉桥钢-混结合段产生空间分布的翘曲正应力，使得钢板和RPC的最大正压应力较压弯时增加30%。
[Abstract]:The main span of the hybrid beam cable-stayed bridge is the concrete main beam, the main span is the steel main beam and the two main beams are connected and converted by the steel mixing section near the bridge tower. The main beam of the mixed girder cable-stayed bridge is different material, and the steel mixing section is the key part of the mixed beam cable-stayed bridge, its structure form and mechanical characteristics are complex. The design and construction of the mixed beam cable-stayed bridge will face new problems. Therefore, the engineers and researchers need to study the mechanical performance and construction control of the mixed girder cable-stayed bridge.
The mixed girder cable-stayed bridge mostly uses Twin Towers, space cable surface and semi floating system. The steel box girder of the main span steel box girder is usually assembled as a segment as a whole, while the main span steel box girder is used as a segment as a whole, while the cable-stayed bridge used in this paper is a single tower, single cable surface, a tower beam pier solid knot system, and the main beam in the suspension construction, the steel inside a cable distance steel. The section of box girder will be divided into two stages of lifting construction. Large span, single tower, single cable surface, wide box and other special points will make the steel mixing section bear greater torque during the bridge operation, and the subsection hoisting construction of the main span steel box girder will make the assembling process become complicated.
In this paper, taking the second bridge of the six Treasury Nu River in Yunnan as the project background, the key technology of the mechanical performance and construction control of the single tower single cable plane mixed beam cable-stayed bridge is studied. The main contents are as follows:
(1) establish the MIDAS finite element model of the second bridge of Nu River and study its mechanical characteristics.
(2) according to the actual situation of the project, the optimization of the construction process and the method of installing the cable force and the optimal construction plan are studied.
(3) the key parameters in the construction control of the hybrid girder cable-stayed bridge and the construction control method of the main span steel box girder hoisting are studied.
(4) establish the ANSYS finite element model of the steel-concrete joint section and study its stress mechanism.
The main conclusions are as follows:
(1) tower girder pier consolidation system should be adopted for single tower single cable plane hybrid girder cable stayed bridge.
(2) the construction of steel concrete mixing section of single tower and single cable plane hybrid girder cable-stayed bridge can be simplified.
(3) the cantilever hoisting process of the main span steel box girder of the hybrid girder cable-stayed bridge can be optimized by the method proposed in this paper.
(4) the construction of cable-stayed bridges should be strictly controlled according to the calculated length of unstressed cables, precast alignment and installation alignment.
(5) the steel and concrete combination section has good torsional performance, of which the steel plate bears 20 to 30% torque, and the RPC takes 70 to 80% torque.
(6) the steel mixing section of the mixed beam cable-stayed bridge under the torque action of the tower girder pier produces the warping positive stress in the space distribution, which makes the maximum positive pressure of the steel plate and RPC increase by 30%..
【学位授予单位】：湖南大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U448.27

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