1 September 1999
and Other Structures" for NAVFAC buildings. Earthquake loads are based on the
requirements of TI 809-04, "Seismic Design for Buildings," and FEMA 302, "NEHRP
Recommended Provisions for Seismic Regulations for New Buildings and Other Structures."
1-7. COMBINATION OF LOAD EFFECTS. The effect on the structure and its components
due to gravity loads and seismic forces will be combined in accordance with the following
factored load combinations, and in accordance with TI 809-04 guidelines:
1.2 D + 1.0 E +0.5 L + 0.2 S
(ASCE 7, Paragraph 2.3.2)
0.9 D + 1.0 E
(ASCE 7, Paragraph 2.3.2)
D = dead load
E = earthquake load as defined by FEMA 302
L = live load as defined by TI 809-01
S = snow load as defined by TI 809-01
For the above load combinations the strength reduction factors (φ) for concrete will be in
accordance with Appendix C of ACI 318-95. All other load combinations (non-seismic load
combinations) will be in accordance with the applicable material design standard (ACI 318 for
concrete, AISC for steel, etc.).
1-8. STRENGTH AND SERVICEABILITY PERFORMANCE OBJECTIVES. General require-
ments with respect to strength and serviceability are indicated in the following paragraphs.
Specific requirements on strength and serviceability with respect to the various types of
building systems and construction materials are provided in the following chapters of the TI.
a. Strength. Buildings and other structures, and all parts thereof, will be designed to
support safely the loads and load combinations indicated above.
b. Serviceability. Structural systems and members thereof will be designed to have
adequate stiffness to limit deflections, lateral drift, vibration, or any other deformations that
adversely affect the intended use and performance of the building. Building designs must also
consider deformation loads such as temperature, differential settlement, creep, and shrinkage.
such as crack control joints, will be considered an essential part of the building design. In
addition buildings, when necessary, will be capable of withstanding severe environmental
effects without incurring damage or deterioration that would reduce the building's service life.
c. Deflection and Drift Limits. Deflections of structural members will not be greater than
allowed by the applicable material standard (ACI, AISC, etc.). Deflection limits are needed to
restrict damage to ceilings, partitions, and other fragile nonstructural elements. Therefore, the
deflection over span length (l) will not exceed that permitted by Table 1-4. Drift limits applicable
to earthquake loading are provided in Table 6-1 TI 809-04. In certain cases, drift limits lower
than those specified in TI 809-04 will be required to restrict damage to partitions, stair and
shaft enclosures, glass, and other fragile nonstructural elements.