UFC 4-023-03
25 January 2005
CHAPTER 5
STRUCTURAL STEEL DESIGN REQUIREMENTS
This chapter provides the specific requirements for designing a structural
steel building to resist progressive collapse. Appendix D demonstrates the application
of the structural steel design requirements for a 5-story office building.
For composite construction, such as concrete deck slabs on steel beams,
sheet steel decking with an integral slab, and columns reinforced with structural steel
shapes, the application of both the requirements of this chapter and those provided for
reinforced concrete in Chapter 4 are required. For a concrete deck slab on steel beam
in which the slab is used to provide internal tie capacity, the floor system and roof
system would be required to meet the internal tie requirements of Section 4-2, while the
steel frame would be required to meet the other tie requirements (vertical, peripheral,
and external column) and the AP requirements of this chapter.
5-1
MATERIAL PROPERTIES FOR STRUCTURAL STEEL.
Apply the appropriate over-strength factors to the calculation of the design
strengths for both Tie Forces and the Alternate Path method. Over-strength factors are
given in Table 5-1.
Table 5-1 Over-Strength Factors for Structural Steel
Ultimate Over-
Yield Over-
Structural Steel
Strength Factor, Ωu
Strength Factor, Ωy
Hot-Rolled Structural Shapes and Bars
ASTM A36/A36M
1.05
1.5
ASTM A573/A572M Grade 42
1.05
1.3
ASTM A992/A992M
1.05
1.1
All other grades
1.05
1.1
Hollow Structural Sections
ASTM A500, A501, A618 and A847
1.05
1.3
Steel Pipe
ASTM A53/A53M
1.05
1.4
Plates
1.05
1.1
All other products
1.05
1.1
5-1
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