perform analysis of lateral load resisting systems Flashcards
seismic load effects - additive - max
E = Eh + Ev or E = ρ Qe + .2 Sds D
seismic load effects - counteractive - min
E = Eh - Ev or E = -ρ Qe - 0.2 Sds D
horizontal seismic load effect, Eh
Eh = ± ρ Qe where Qe is horizontal seismic forces ρ = 1.3 for SDC = D, E, or F
verticle seismic load effect, Ev
Ev = ± 0.2 Sds D, exceptions it is permited to use Ev = 0 for either where Sds ≤ 0.125
seismic load effect including over strength factor, Ω0
Em = Emh + Ev, Em = Ω Qe + 0.2 Sds D
seismic load effect including over strength factor, Ω0
Em = - Emh - Ev, Em = - Ω Qe - 0.2 Sds D
horizontal seismic load effect w overstrength factor, Emh
Emh = ± Ω0 Qe
strength design or load & reistance factor design
see pg. 1-67
alternative basic (ASD) load combinations
see pg 1-68
load combinations with over strength factor
see pg 1-68
calculated deflection of a level, δx
δx = Cd δxe / I
calculated story drift, ∆x
∆x = δx - δx-1 given δx is amplified top & amplified at bottom
calculated (max inelastic) 2nd story drift
calculated ∆2 = δ2 - δ1
story drift limit, ∆ax
see pg. 1-54
diaphragm design force, Fpx
Fpx = (∑ Fi / ∑Wi) x Wpx with ≤ 0.4 Sds I Wpx max and ≥ 0.2 Sds I Wpx min.