Seismic Load Effects and Combination per ASCE 7-16 §12.4

Symbols

E = Seismic load effect
Eh = Horizontal seismic load effect
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
QE = Combined applied design force on the horizontal seismic effects
ρ = Redundancy factor,
Ωo = Overstrength factor


Seismic Load Effect

The seismic load effect ,E, is calculated in appropriate combinations in accordance with Eq. (12.4-1) and Eq. (12.4-2) as follows:

Horizontal Seismic Load Effect

The horizontal seismic load effect, Eh, is calculated in accordance with Eq. (12.4-3) as follows:

Vertical Seismic Load Effect

The vertical seismic load effect, Ev, is determined in according to Eq. (12.4-4a) for buildings that are seismic design categories A and B.

The vertical seismic load effect, Ev, is determined in according to Eq. (12.4-4b) for buildings that are seismic design categories C, D, E and F.

Seismic Load Effects Including Overstrength

The seismic load effect including overstrength ,Em, is calculated in appropriate combinations in accordance with Eq. (12.4-5) and Eq. (12.4-6) as follows:

Horizontal Seismic Load Effect Including Overstrength

Eq. (12.4-7) is applied to determine the effect of horizontal seismic forces including overstrength, Emh.

 

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