Combining Horizontal and Vertical Earthquake Effects per ASCE 7-16 with ideCAD

How does ideCAD define combined horizontal and vertical seismic load effect, according to ASCE 7-16, for two earthquake directions?

• Seismic load effects including overstrength is determined automatically.

Symbols

E_m = Combined applied design force on the horizontal and vertical seismic load effects
E_mh= The effect of horizontal seismic forces including overstrength
E_v = Vertical seismic load effect
Ω_o = Overstrength factor

Seismic Load Effects Including Overstrength

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

12.4.3.1 Horizontal Seismic Load Effect Including Overstrength

Eq. (12.4-7) is applied to determine the effect of horizontal seismic force,s including overstrength, E_mh.

The maximum effect of seismic forces, Q_E, 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, E_v, are considered in accordance with Section 12.4 to obtain the seismic load effect, E. These orthogonal combinations should not be confused.

Next Topic

Vertical Seismic Load Effect per ASCE 7-16 §12.4.2.2

Related Topics

• Analysis Procedure Selection per ASCE 7-16 §12.6

• Modeling Criteria per ASCE 7-16 §12.7

• Modeling of Masses per ASCE 7-16 with ideCAD

• Effective Section Stiffness per ASCE 7-16 §12.7.3

• Equivalent Lateral Force Method (ELF) per ASCE 7-16 §12.8