Technical aspects of cables stayed bridges Essay

Technical aspects of cables stayed bridges - Essay Example In simple terms, cable-stayed bridges carry mainly vertical loads that act on the girder. Immediate support for the girder is provided by the stay cables so that the bridge can extend over a long distance. Basically, the structure of a cable-stayed bridge is such that it is constructed of a series of overlapping triangles made up of the tower, the pylon, the girder and the cables, which are usually under axial forces, and are considered flexural and efficient. The cables are always under tension whereas the girder and the pylon are under compression. This report looks at the history of cable stay bridges, examines the configuration and design structure, technical requirements, offers a description of various bridge structures and an analysis of the bridge structures. The report concludes by offering recommendations for stay-cable design, installation and testing. Introduction A first glance at cable-stayed bridges raises some interesting questions from both the public and bridge engi neers, who find them technically challenging and innovative, as well as the architects. The cable-stayed bridges attracted public attention when the Stromsund Bridge in Sweden was completed. ... Basically, the structure of a cable-stayed bridge is such that, it is made up of a series of overlapping triangles, made up of the tower, the pylon, the girder and the cables, which are usually under axial forces, and are usually considered flexural and efficient. The cables are always under tension whereas the girder and the pylon, under compression (Dayaratnam 2000). Overtime, cable-stayed bridges have become very popular in bridge engineering; there are more than seven hundred cable-stayed bridges in the world today. With advancement in technology and architectural design, the length of cable-stayed bridges has significantly increased over the years. For instance, the first major cable-stayed bridge built in 1955, the Stromsund Bridge in Sweden, spanned 183m; in the 1970’s, the Neuenkamp bridge in Germany spanned 350m and was considered the longest one then until the 1980s when another bridge, the Alex Fraser-Annacis Island bridge, spanned 465m was completed (Denney Pate & Rohleder, Jr., 2008). This was, however, surpassed in 1994 by the Normandie bridge that spanned 856m. Today, the longest span cable-stayd bridge is the Russky Bridge, in Vladivostok, Russia, spanning 1,104m, completed in 2012 (Svensson 2012). Configuration of Cable-Stayed Bridges The concept of cable-stayed bridges as illustrated in Figure 1 was that cable suspension was to be used to replace piers as intermediary support for girder, so that it could withstand the vertical load over a long span or distance (Morgenthal & Yamasaki 2010). As a result, the first cable-stayed bridges spaced stay cables far apart based on the maximum girder strength. The