摘要
随着科学技术和交通事业的发展,预应力混凝土连续刚构桥以其施工简便、造价经济、受力合理、行车舒适等独特优势在近年来得到了迅速崛起。然而,随着这种桥梁大量使用后,很多现役的此类桥梁出现了腹板开裂和跨中下挠过大的问题,已直接威胁着连续刚构桥的正常使用。在大跨度连续刚构桥中尝试采用体内外混合配索,充分利用体外索可更换和补张拉等优点,以求解决或减轻目前连续刚构桥所出现的问题。
本文以重庆新滩綦江大桥为工程背景,在大跨度连续刚构桥中开展体内外混合配索研究。在充分总结体外预应力桥计算理论的基础上,分别对背景工程中的左右两幅桥开展体内配索与体内外混合配索对比设计;并通过对体内预应力桥和体内外混合配索桥的有限元对比分析,总结出两种不同配索体系桥的不同受力特点,得出设计成果满足有关规范要求。随后对体内外混合配索在控制斜裂缝的开展、抑制跨中下挠和经济性三方面的特点进行了探讨。同时,通过体外预应力在本工程中的实施,总结出体外预应力的施工工艺,以及施工中的其它关键技术。
本论文的相关研究成果不仅直接支持和指导了依托工程的设计和施工,同时也为体外预应力技术在我国桥梁中的应用提供理论参考与实践。
Along with Scientific technology and the development of transport, prestressed concrete continuous rigid frame bridge with its construction is simple, cost economy, reasonable force, comfortable journey to our unique advantages in recent years have been rapidly rising. However, with extensive use of this bridge, many of large span continuous ridge frame bridge widespread produce cracks in the webs and deflections in the middle of span.This have threated to the continuous rigid frame bridge normal use. The large span continuous rigid frame bridge is designed with a new prestressed system——the internal and external prestressed technique.Make full use of the advantages of external cable can be replaced and repeat Tension, in order to solve or alleviate the current problems.
This paper regard the Chong Qing Xitan Qijiang bridge as an example, Research of the internal and external prestressed technique in the large span continuous ridge frame bridge. On the basis of aggregating calculation theory fully, comparedly designing two bridges in background works Project.One is designed with internal and external prestressing, whereas the other is internal. Through comparison analysising, the characteristics of this two bridges are gained. Moreover, the design results meet the requirements of relevant specifications. From controlling ramp cracks, repressing deflections in the middle of span and economy, the advantages of the internal and external prestressed technique has been discussed. At the same time, through implementing external prestressed in this project, the technology and other key points in external prestressed bridge construction have been summed up.
In this paper, the relevant research results not only support the design and construction of this background projects directly, but also give a good reference and guide on Building external prestressed bridge in China.
引文
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