特大体量公铁两用矮塔斜拉桥箱—桁组合结构的研究

发布时间：2018-05-01 21:13

本文选题：公铁两用 + 矮塔斜拉桥　；参考：《中南大学》2014年硕士论文

【摘要】：摘要：拟建的WHS桥是一座(98+238+588+224+84)m的公铁两用双主桁双索面矮塔斜拉桥。该桥分两层,上层为8车道公路,下层为4线铁路,它将是当前国内外跨度和体量都最大的公铁两用矮塔斜拉桥。为提高桥梁刚度,上层桥面采用正交异性板开口钢箱梁；下层桥面采用正交异性板闭口钢箱梁；主桁杆件与上、下层钢箱梁结合成整体形成箱-桁组合结构。这种结构形式国内外未有先例,结构构造和受力情况都很复杂。本文对该桥的结构形式、变形和受力特征、主梁施工工法进行了研究,主要工作和成果如下： 1.对WHS桥有限元模拟方法进行了研究,选用空间杆系结构法建立全桥有限元模型,对上层公路正交异性板开口钢箱梁采用单层梁格法模拟,对下层铁路正交异性板封闭钢箱梁采用双层梁格法模拟。 2.研究了WHS桥在活载作用下的变形和受力性能,结果表明：由于采用了箱-桁组合结构,该桥在铁路和公路静活载共同作用下最大竖向位移为985mm,挠跨比1/597。 3.研究了铁路箱梁底板、上弦箱刚度、主桁刚度、斜拉索刚度、桥塔刚度、斜拉索锚固于上弦和下弦等因素对活载作用下WHS桥变形和受力的影响。结果表明：铁路钢箱梁对桥梁刚度有较大贡献,钢箱梁底板不可或缺；上弦箱、主桁、斜拉索和桥塔等的刚度对桥梁的变形和受力也有明显的影响；斜拉索锚于上弦时桥梁的变形和受力状态优于锚于下弦。 4.对该桥提出了三种主梁施工工法并研究了与之相关的桥梁在恒载作用下的变形和受力,对三种工法作了综合比较。结果表明：一次成桥的工法稳定性较好,施工过程较易控制；两种二次成桥的工法均需严格控制拼装顺序并及时调整索力；三种工法在恒载、恒载与活载共同作用下塔柱塔顶外侧均出现拉应力。 5.对WHS桥的结构合理性作出了评价并提出了优化和细化的建议。该桥结构形式和构造总体合理,整体刚度和受力总体满足要求；塔柱塔顶应采取措施局部加强、或考虑将其上横梁去掉或下移至锚索以下。本文的研究成果为WHS桥的设计提供了依据,对其他类似桥梁也有参考价值。图74幅,表33个,参考文献60篇。
[Abstract]:Abstract: the proposed WHS bridge is a (98+238+588+224+84) m double main truss double cable plane short tower cable-stayed bridge with double main truss. The bridge is divided into two layers, the upper layer is 8 lane highway, and the lower layer is 4 line railway. It will be the current domestic and foreign long span and the largest steel double use short tower cable-stayed bridge. In order to improve the bridge stiffness, the upper deck adopts orthotropic plate opening. The steel box girder of the mouth is a steel box girder with orthotropic plate closed; the main truss member and the upper and lower steel box girder are formed to form a box truss composite structure. This structure is not precedent at home and abroad. The structure and structure and the stress condition are very complex. This paper is on the structure, deformation and stress characteristics of the bridge, and the construction method of the main beam. The main work and results are as follows:
1. the finite element simulation method of WHS bridge is studied. A full bridge finite element model is established by using the spatial bar system structure method. A single beam grid method is used to simulate the orthotropic slab open steel box girder on the upper highway, and the double beam grid method is used to simulate the bottom rail orthotropic plate closed steel box girder.
2. the deformation and stress performance of the WHS bridge under the active load are studied. The results show that the maximum vertical displacement of the bridge is 985mm under the combined action of the static and live loads of the railway and the highway, and the deflection span ratio is 1/597..
3. the influence of the stiffness of the upper chord box, the rigidity of the upper chord box, the stiffness of the main truss, the stiffness of the cable-stayed cable, the stiffness of the bridge tower, the anchorage of the cable-stayed cable to the upper and lower chords on the deformation and stress of the WHS bridge under the live load. The results show that the steel box girder has a great contribution to the stiffness of the bridge, and the steel box girder floor is indispensable; the upper chord box, main truss, inclined cable and the cable are necessary. The stiffness of bridge tower also has a significant effect on the deformation and stress of the bridge; when the cable is anchored to the upper chord, the deformation and stress state of the bridge is better than that of the anchor string.
4. the construction method of three main beams was put forward and the deformation and stress of the bridge related to the bridge were studied under the constant load. The three methods were compared synthetically. The results showed that the construction method of the first bridge was more stable and the construction process was easier to control; two kinds of two construction methods needed to strictly control the sequence of assembly and adjust it in time. Cable tension; the three methods are tensile stress at the top of the tower column under the combined action of dead load, dead load and live load.
5. the structure rationality of the WHS bridge is evaluated and the suggestion of optimization and refinement is proposed. The structure and structure of the bridge are generally reasonable, the overall stiffness and the force are generally satisfied; the top of the tower tower should be partially strengthened, or the above beam should be removed or moved down to the anchor cable.
The research results in this paper provide a basis for the design of WHS bridge, and have reference value for other similar bridges. There are 74 tables, 33 tables and 60 references.

【学位授予单位】：中南大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U448.27

【参考文献】