# Tag: Cable Erection of Cable-Suspended Bridges

The ease of erection of suspension bridges is a major factor in their use for long spans. Once the main cables are in position, they furnish a stable working base or platform from which the deck and stiffening truss sections can be raised from floating barges or other equipment below, without the need for auxiliary falsework. For the Severn Bridge, for example, 60-ft box-girder

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# Tag: Cable Seismic Analysis of Cable-Suspended Structures

For short-span structures (under about 500 ft) it is commonly assumed in seismic analysis that the same ground motion acts simultaneously throughout the length of the structure. In other words, the wavelength of the ground waves are long in comparison to the length of the structure. In long-span structures, such as suspension or cable-stayed bridges, however, the structure could be subjected to different motions

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# Tag: Cable Preliminary Design of Cable-Stayed Bridges

In general, the height of a pylon in a cable-stayed bridge is about 1⁄6 to 1⁄8 the main span. Depth of stayed girder ranges from 1⁄60 to 1⁄80 the main span and is usually 8 to 14 ft, averaging 11 ft. Live-load deflections usually range from 1⁄400 to 1⁄500 the span. To achieve symmetry of cables at pylons, the ratio of

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# Tag: Cable Statics of Cables

The following summary of elementary statics of cables applies to completely flexible and inextensible cables but includes correction for elastic stretch. The formulas derive from the fundamental differential equation of a cable shape H  horizontal component of   tension produced by w w  distributed load, which may vary with x Two cases are treated: catenary, the shape taken by a cable when

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# Tag: Cable Corrosion Protection of Cables

In the past, the method of protecting the main cables of suspension bridges against corrosion was by coating the steel with a red lead paste, wrapping the cables with galvanized, annealed wires, and applying a red lead paint. This method has met with a varying degree of success from excellent for the Brooklyn Bridge to poor for the General U. S. Grant Bridge

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# Tag: Cable Cable Saddles, Anchorages and Connections

Saddles atop towers of suspension bridges may be large steel castings in one piece (Fig. 15.35) or, to reduce weight, partly of weldment (Fig. 15.36). The size of the saddle may be determined by the permissible lateral pressures on the cables, which are a function of the radius of curvature of the saddle. Other saddles of special design may be required at side piers

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# Tag: Cable Cables

The concept of bridging long spans with cables, flexible tension members, antecedes recorded history (Art. 15.1). Known ancient uses of metal cables include the following: A short length of copper cable discovered in the ruins of Ninevah, near Babylon, is estimated to have been made in about 685 B.C. in the Kingdom of Assyria. A piece of bronze rope was discovered in the ruins

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# Tag: Cable Cable Structures

High-strength steel cables are very efficient for long-span roof construction. They resist loads solely by axial tension. While the cables are relatively low cost for the load-carrying capacity provided, other necessary components of the system must be considered in making cost comparisons. Costs of these components increase slowly with increasing span. Consequently, the larger the column-free area required, the greater the likelihood that a

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# Tag: Cable Cable Construction

Cables, more commonly referred to as wire rope, are sometimes used in buildings to support long-span roofs, to suspend floorbeams from upper levels, and as bracing members to resist wind loads. Wire rope is made of three basic components: wires, strands, and a core. Each rope end usually is equipped with a fitting, an accessory for attaching the cable to an anchorage or part

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