Home / Tools / ASCE 7-22 Nonstructural Fp 🇺🇸 US · B

ASCE 7-22 Seismic Force on Nonstructural Components (§13.3.1)

ASCE 7-22 rewrote the F_p equation: F_p = 0.4·S_DS·I_p·W_p·(H_f/R_μ)·(C_AR/R_po) (Eq. 13.3-1). The floor amplification H_f depends on the building period, and R_μ on the ductility of the building's seismic system.

Inputs

S_DS (g)

I_p

W_p (lb)

Attachment height z (ft)

Roof height h (ft)

Building period T_a (s, blank = Eq. 13.3-5)

Building R

Building I_e

Building Ω₀

C_AR (Table 13.5-1 / 13.6-1)

R_po

Location

Results

Quantity	Value	Clause

Sources and verification

EquationsEq. 13.3-1, the limits 1.6·S_DS·I_p·W_p and 0.3·S_DS·I_p·W_p, H_f (13.3-4, 13.3-5) and R_μ (13.3-6) are confirmed in two free sources: HCAI (California) SCU webinar handout on CBC 2025 changes (2025) and FEMA P-2192-V1/V2, 2020 NEHRP design examples (Ch. 8, public domain). ASCE 7-22 is cited by clause number only.

ASCE 7-22 vs NEHRPR_μ = [1.1·R/(I_e·Ω₀)]^½ ≥ 1.3. FEMA P-2192 notes that ASCE 7-22 added I_e to the 2020 NEHRP form — tools based on the NEHRP text overstate R_μ for Risk Category III/IV buildings.

AnchorsAll five FEMA P-2192-V1 Chapter 8 examples — precast panel (body and fasteners), egress stair (flight, landing, fasteners), HVAC fan (rigid and on vibration isolators), piping (pipe and supports) and elevated vessel (vessel and frame): thirteen results, each within 0.3 % of the book, with the same governing equation. See the 2020 NEHRP examples page. HCAI R_μ column (I_e = 1.5): steel SMF 1.40, EBF 1.71, special RC wall 1.30 (lower limit).