Combining Horizontal and Vertical Earthquake Effects
Seismic load effects including overstrength is determined automatically.
Symbols
Em = Combined applied design force on the horizontal and vertical seismic load effects
Emh= The effect of horizontal seismic forces including overstrength
Ev = Vertical seismic load effect
12.4.3 Seismic Load Effects Including Overstrength
1.E is taken as equal to Em as determined in accordance with Eq. (12.4-5). It applies in load combination 6 in Section 2.3.6 or load combinations 8 and 9 in Section 2.4.5.
2. E is taken as equal to Em as determined in accordance with Eq. (12.4-6). It applies in load combination 7 in Section 2.3.6 or load combination 10 in Section 2.4.5.
12.4.3.1 Horizontal Seismic Load Effect Including Overstrength
Eq. (12.4-7) is applied to determine the effect of horizontal seismic forces including overstrength, Emh.
The maximum effect of seismic forces, QE, from orthogonal load combinations is modified by the redundancy factor, ρ, or the overstrength factor, Ω0, where required, and the effects of vertical seismic forces, Ev, are considered in accordance with Section 12.4 to obtain the seismic load effect, E. These orthogonal combinations should not be confused.
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