Structural Engineering Slide Library

Set C: Cable and Suspension Structures

This set of slides illustrates many of the important aspects of tension structures, including cable and suspension systems, as used in structural engineering. It includes the following general topics:

Tension and suspension structures are a very important class of structure, particularly for long-span systems, and hence should be introduced early in a course of structural analysis. This must be done with caution on account of the nonlinear characteristics of many long-span tension and suspension structures. But the comparison with arch structures can be made directly in studying the analysis, and the one-to-one relationship between the arch and the tension structure is obvious in the case of the relatively stiff system where deflections do not significantly alter the distribution of internal forces (that is, systems which can be taken as linear). A clear example of this comparison can be seen between the three-hinged tension structure of slide C10 in this set with the three-hinged arch structures in Set B: Arch Structures, and this can form the basis for an elementary understanding of some of the characteristics of suspension bridges.

The early days of suspension bridge construction are interesting, and examples are included of early chain bridges from England and the United States. To illustrate the design of a typical modern suspension bridge, a relatively small bridge is used, the Maysville Bridge in Kentucky. Following this, examples of some long-span bridges are given, both with and without stiffening trusses. The design of the new Tacoma Straights Bridge is shown to illustrate the precautions that were taken to prevent a repetition of the aerodynamic failure of the previous bridge. The Bosporus Bridge is used as an example of current suspension bridge design practice. (Note: The Forth Road Bridge in Scotland is used as an example of bridge construction in Set G: Structures Under Construction, where it is shown at different stages of construction, from the cable-spinning, to the truss construction, to the finished bridge.) Cable-stayed bridges are illustrated by both early and recent examples in both steel and reinforced concrete.

The use of cable and suspension systems in building construction is illustrated by long-span roofs, cable-net systems, and by a multi-story building with suspended floors.