Building Design and Construction Handbook - Merritt - Ventech!

1.12 SECTION ONE
FIGURE 1.3 Structural-steel skeleton framing for a multistory building.
(Courtesy of the American Institute of Steel Construction.)
other horizontal members at a higher level.) The system comprising decks, beams,
and bearing walls is known as load-bearing construction (Fig. 1.1). The system
composed of decks, beams, and columns is known as skeleton framing (Fig. 1.3).
Both types of systems must be designed to transmit to the foundations vertical
(gravity) loads, vertical components of inclined loads, horizontal (lateral) loads, and
horizontal components of inclined loads. Vertical walls and columns have the appropriate
alignments for carrying vertical loads downward. But acting alone, these
structural members are inadequate for resisting lateral forces.
One way to provide lateral stability is to incorporate in the system diagonal
members, called bracing (Fig. 1.3). Bracing, columns, and beams then work together
to carry the lateral loads downward. Another way is to rigidly connect beams
to columns to prevent a change in the angle between the beams and columns, thus
making them work together as a rigid frame to resist lateral movement. Still another
way is to provide long walls, known as shear walls, in two perpendicular
directions. Lateral forces on the building can be resolved into forces in each of
these directions. The walls then act like vertical beams cantilevers) in transmitting
the forces to the foundations. (See also Art. 3.2.4.)
Because of the importance of the structural system, the structural members
should be protected against damage, especially from fire. For fire protection, bracing