300-500米跨径桥梁的适宜结构体系

发布时间：2019-06-12 03:06

【摘要】：目前300~500m跨径桥梁主要的结构体系有连续刚构桥、拱桥、斜拉桥和悬索桥，且大多依赖普通的混凝土、钢结构，，其中连续刚构桥主跨尚未突破400m。超高性能混凝土（UHPC）具有强度高、收缩徐变小、耐久性强、体积稳定性好的优点，将其应用到桥梁结构中，可以显著降低结构自重，提高桥梁跨越能力，降低全寿命成本。本文提出将UHPC应用到大跨梁式结构体系中，以期实现梁式结构体系跨越能力的突破，并重新定义基于可持续性分析与全寿命分析的300~500m跨径桥梁适宜的结构体系。为此，本文作者主要做了以下研究工作：（1）首先明确了桥梁结构体系的概念、分类、发展演进及适用范围，为开展结构体系的研究奠定基础。接着详细介绍了UHPC的材料特性、可持续性、经济性及其在国内外的工程应用情况，阐明UHPC在桥梁工程中尤其是大跨结构方面具有广阔的应用前景。（2）引入超大跨径UHPC连续箱梁桥设计理念，选取主跨在300~500m范围内具有代表性的梁式桥、拱桥、斜拉桥、悬索桥结构体系实桥案例，在科研团队研究的基础上，以实桥为工程背景进行UHPC连续箱梁桥概念设计。（3）分别对四个不同主跨的UHPC连续箱梁桥案例进行有限元整体受力分析，并进行强度与刚度验算，确保结构设计安全合理。有限元分析显示，四个跨度的设计桥梁受力合理，结构体系安全可行。（4）根据桥梁结构材料用量，对实桥与设计桥梁进行初始建造成本及能量消耗情况进行计算，并做方案对比。结果表明：UHPC连续箱梁桥方案可持续性效益明显优于实桥，经济性介于拱桥与其他三种结构体系实桥之间。（5）接着对实桥与设计桥梁主要构件进行寿命预测，据此确定桥梁构件在整个使用寿命周期内的维护、更换时间和频率，进而对桥梁方案的全寿命成本进行计算和对比。分析表明：UHPC连续箱梁桥具有良好的耐久性，使用寿命较长，其后期维护成本百分比低于实桥，100年寿命成本介于拱桥与其他三种结构体系实桥之间，200年寿命成本明显低于所有实桥。
[Abstract]:At present, the main structural systems of 300 m span bridge are continuous rigid frame bridge, arch bridge, cable-stayed bridge and suspension bridge, and most of them rely on ordinary concrete and steel structure, in which the main span of continuous rigid frame bridge has not yet broken through 400 m. Ultra-high performance concrete (UHPC) has the advantages of high strength, small shrinkage and creep, strong durability and good volume stability. Its application to bridge structure can significantly reduce the weight of the structure, improve the span capacity of the bridge and reduce the whole life cost. In this paper, UHPC is applied to the long-span beam structure system in order to realize the breakthrough of the span capacity of the beam structure system, and the suitable structural system of 300 m span bridge based on sustainability analysis and whole life analysis is redefined. Therefore, the author has done the following research work: (1) firstly, the concept, classification, development, evolution and applicable scope of bridge structure system are clarified, which lays the foundation for the research of structural system. Then the material characteristics, sustainability, economy and engineering application of UHPC at home and abroad are introduced in detail, and it is expounded that UHPC has a broad application prospect in bridge engineering, especially in long-span structures. (2) the design concept of large span UHPC continuous box girder bridge is introduced, and the real bridge cases of beam bridge, arch bridge, cable-stayed bridge and suspension bridge structure system with main span in the range of 300 m are selected. On the basis of the research team, the conceptual design of UHPC continuous box girder bridge is carried out with the real bridge as the engineering background. (3) the finite element overall force analysis of four UHPC continuous box girder bridges with different main spans is carried out, and the strength and stiffness are checked to ensure the safety and reasonableness of the structural design. The finite element analysis shows that the stress of the four-span design bridge is reasonable and the structural system is safe and feasible. (4) according to the amount of bridge structure material, the initial construction cost and energy consumption of the real bridge and the designed bridge are calculated, and the schemes are compared. The results show that the sustainability benefit of UHPC continuous box girder bridge is obviously better than that of real bridge, and the economy is between arch bridge and other three kinds of structural systems. (5) then the life prediction of the main components of the real bridge and the design bridge is carried out, according to which the maintenance, replacement time and frequency of the bridge components in the whole service life cycle are determined, and then the whole life cost of the bridge scheme is calculated and compared. The analysis shows that the UHPC continuous box girder bridge has good durability and long service life, the percentage of maintenance cost in the later stage is lower than that of the real bridge, the life cost of 100 years is between the arch bridge and the other three kinds of structural systems, and the life cost of 200 years is obviously lower than that of all the real bridges.
【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】：U442.5

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