erection. Fabrication involves the processing of raw materials to form the finished members of the structure. Erection includes all rigging, hoisting, or lifting of members to their proper places in the structure and making the finished connections between members.

A wide variety of structures are erected using structural steel. Basically, they can be listed as buildings, such as PEBs, bridges, and towers; most other structures are modifications of these three.

STEEL BUILDINGS

Three basic types of steel construction are used today. These may be designated as wall-bearing construction, skeleton construction, and long-span construction. In wall-bearing construction, exterior and interior masonry walls are used to support structural members, such as steel beams and joists, which carry the floors and roof. Note that while this section of your TRAMAN covers steel structures, wall-bearing construction is applicable to nonsteel structures as well. Wall-bearing construction is one of the oldest and most common methods in use. Although modem developments in reinforced concrete masonry make the use of this method feasible for high-rise structures, wall-bearing construction is normally restricted to relatively low structures, such as residences and light industrial buildings.

A tall building with a steel frame, as shown in figure 8-49, is an example of skeleton construction. In this

Figure 8-49. - Structural steel skeleton construction.