Papers by Keyword: Steel Box Girder

Abstract: In practical steel box girder, the fatigue cracks are inevitably existed in steel bridges after they are burdened with the overloading vehicles and larger numbers of automobiles. How to efficiently detect the fatigue cracks, especially the initial fatigue cracks, become one of the most important question to be solved for the steel box girder. HIROX testing system is based on three dimensional micro detection technique, which was successfully used into the domains of aeronautics and astronautics. Three dimensional micro detection scheme of fatigue cracks in steel box girder with HIROX testing system is studied in this paper. Through the data from the testing design, the important characteristic width and length of the fatigue crack can be achieved, which can be used for the grasping of the mechanism of the steel box girder.

Abstract: The fatigue cracks are inevitably existed in steel bridges after they are working for a fairly short time because of the environmental pollution, overloading vehicles and larger numbers of automobiles. Due to the fact that the scholars have put few emphases on the influence of corrosive environment which inevitably affects the fatigue property of steel bridge, an experiment design of corrosive and fatigue property of steel box girder with the specific environment controlling equipment is taken into account. Through the data from the experiment design, the important residual strain can be gained, which can be used for the analysis of the damage developing regularity.

Abstract: Houdingxiang No. 3 Bridge is a 4-span steel box girder bridge. After the incremental launching construction, the bridge has to be lowering to the support bear, the lowering construction is divided into three stages. At first the launching equipment is used to lower 80cm, the next the jack with load capacity of 180 tons is used to lower 110cm, finally three-direction-jack with load capacity of 200 tons is used to lower 20cm. mechanical analysis on lowering the bridge used jacks with the load capacity of 180 tons and 200 tons is respectively carried out by FEM software ABAQUS, and the result shows that this kind of lowering technique is safe and reliable, it meets the construction demand.

Abstract: With the continued rapid economic development in recent years, Urumqi, vehicle scale continues to expand, prompting the city traffic was a rapid growth trend, Outer Ring Road as a fast loop only existing within the city limits, borne traffic has far exceeded the original design prediction traffic volume and the actual capacity, resulting in a number of sections, interchange nodes, often made of ramp entrances become congested road, the outer ring road to solve the congestion problem, and it needs to be rebuilt to meet the expansion needs of the new era. Urumqi City East Outer Ring Expressway road expansion reconstruction project, for example, to explore the elevated expansion of the project construction methods, summarize experience in construction, hoping to provide a reference for future similar projects.

Abstract: Balanced cantilever construction phases are of great importance for the total life cycle processes of super long-span cable-stayed bridges. For assessment purpose, a systematic study on the reliability evaluation of these phases is carried out. Taking Sutong bridge as the sample structure studied, a series of load and resistance models are then established on the basis of field measurement. Using all these achievements, a typical phase of girder segment 6# lifting is chosen for reliability evaluation. Results of the analysis show that the established models are quite representative and reflect actual random nature perfectly. Furthermore, compared with pylon and stay cables the stiffening girder seems more likely to fail in accordance with reliability index. The major failure mode of it in terms of present analysis is the stability failure due to the action of bending and axial load. Nonetheless, the components on the whole are still in a high level of reliability, which can guarantee the proceeding of construction with efficiency.

Abstract: In order to determine the most unfavorable condition of the steel box girder, ensure its stress and deformation in the safe state, the steel box girder bridge should apply the finite element analysis software to modeling analysis. At the same time, data calculation can provide the theoretical evidence for the factory manufacturing lines. The tender DB01 of the continuous bridge of the Hong Kong-Zhuhai-Macao Bridge provides the backdrop for this essay, using MIDAS/Civil 2012 to do numeral simulation analysis on the hoisting, and then analyzing the stress and deformation of the main beam at the different construction stages. The analysis reveals that the temporary maximum of a hinged steel box girder should be 47.5MPa in the process of construction which is allowed by the stress of the steel Q 345.And after the No.1 beam has been put in the right place and connected, the maximum displacement of the No.6 joint is 19.4mm downward. With the construction stage CS7 completed, the maximum downward displacement is 14.2mm. Making the stress free alignment is superposing the minus figure of the cumulative displacement on the basis of designed line. Each beam segment has been made according to the stress free alignment .Also, after field construction, the ideology of designed lines of the bridge will be brought into reality.

Abstract: According to the design and construction characteristics of steel box concrete girder of a large landscape tower, C40 grade non shrinkage self-compacting concrete meeting engineering requirements was produced. The fresh concrete workability, early age shrinkage are researched, construction technology and detection methods are discussed combined with the practical engineering of steel box concrete girder.

Abstract: Jiu-Jiang Yangtze River Highway Bridge, with a main span of 818m, is another long span hybrid girder cable-stayed bridge which connects Jiang Xi province and Hu Bei province in China. Steel box girder is adopted in main span and north side span, and main girder of south side span and south tower nearby is designed of concrete box girder. The pylon is concrete structure, with the height of 242.3m and H-shape. There are 216 cables used in this bridge, of which are assembled by parallel strands. Jiu-Jiang Yangtze River Highway Bridge began to construct in 2009, and was closed in December, 2012. The bridge opened to traffic officially in the next year. Design concept, construction method and vibration control measures about Jiu-Jiang Yangtze River Highway Bridge are introduced in this article.

Abstract: In the modern urban bridge projects,especially the urban interchange projects and the urban viaduct projects,the long-span curved bridge with the small radius is often inevitably used,considering the transportation under bridges,pipelines and aesthetic factors.This kind of long-span curved bridge with small radius was adopted on the south of Second Ring Road in Chendu of the project of "Two Expressways,Two Extended Roads,Two Ring Roads".The influence,which the change of the parameters on the structure had,was analyzed by using the finite element software of Midas Civil 2010.Then,the parameter which had greatest impact on the inner force of the structure was found.The girder depth is the key parameter in design.

Abstract: Yongjiang railway extra long-span cable-stayed bridge uses the orthotropic deck of steel box girder, and it is the first time that box girder used in the railway cable-stayed bridge, so it is necessary to do a research on the mechanics behavior of this structure with fatigue model test. The accuracy of the fatigue model test data results in the rationality of the test scheme, and the research contents of the test scheme are as follows: the finite element model of steel box girder has been built to analysis the characteristics of the stress distribution, and the fatigue-sensitive regions have been determined; three model schemes have been designed and compared under the principles of stress equivalence and economical efficiency , and the third model has been used as the final fatigue test model . The research result can provide reference for the design of fatigue test model scheme of the same kind of bridge.