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ASCE 41-23 Linear Static Procedure — Pseudo Force & Component Acceptance
Tier 3 evaluation of existing buildings: pseudo seismic force V = C1C2CmSaW, the LSP limit T ≤ 3.5Ts, and component checks — deformation-controlled m·κ·QCE ≥ QUD (with DCR = QUD/κQCE), force-controlled κ·QCL ≥ QUF. C1, C2, Cm, m, κ and QUF are entered from ASCE 41-23 (see the note below). Turkish counterpart: TBDY Chapter 15 / RYTEİE tools.
C1, C2 (§7.4.1.3.1)
Pseudo seismic force
Components
| Name | Type | QG | QE | QCE / QCL | QUF | m | κ |
|---|
Results
a · C1 · C2—
V = C1C2CmSaW—
LSP permitted (T ≤ 3.5Ts)?—
DCRmax (deformation-controlled)—
§7.4.1V = C1C2CmSaW; the LSP is not permitted where T > 3.5Ts (other limits — irregularities, DCR > 3 with weak load paths — must be checked separately).
§7.5.2Deformation-controlled: QUD = QG ± QE, m·κ·QCE ≥ QUD; m-factors apply only to deformation-controlled actions. Force-controlled: κ·QCL ≥ QUF.
C1, C2C1 = 1 + (μstrength − 1)/(aTe²), with Te ≥ 0.2 s and C1 = 1.0 for Te > 1.0 s; C2 = 1 + (1/800)((μstrength − 1)/Te)², C2 = 1.0 for Te > 0.7 s. a = 130 (A, B), 90 (C), 60 (D, E, F) — FEMA 440 values, confirmed by four independent sources. Sources: FEMA 440; Mokarram et al., Turkish J. Civil Eng. 36(1), 2025 (ASCE 41-23 form); California Building Code Ch. 31F. For the new classes BC, CD and DE no source gave a — enter it from ASCE 41-23.
QUFForce-controlled demand QUF = QG ± χQE/(C1C2J), χ = 1.0 (CP) / 1.3 (LS, IO) — the ASCE 41-17 form (SEAU presentation; NRC Canada paper). ASCE 41-23 eliminated the J factor (ASCE's “ASCE 41-23 General Updates” course: force-controlled action and J-factor elimination), so this form is computed only when ASCE 41-17 is selected; for ASCE 41-23 enter QUF from §7.5.2.1.2. For force-controlled rows, a blank QUF is computed from QG and QE.
Near faultA 2025 study of 1,250 systems and 25,000 nonlinear analyses found the coefficient method unconservative by up to 40% near faults (Mokarram et al.).
Entered valuesC1 and C2 depend on μstrength, Te and the site class; ASCE 41-23 adopted the new site classes BC, CD and DE of ASCE 7-22 and their coefficients could not be confirmed from two sources — enter them from §7.4.1.3.1. Likewise QUF (its reduction by J / χ changed between editions), Cm, m and κ come from the standard's tables.
VerifyNIST report “Application of ASCE 41 to a two-story CFS building”, wall L2W1: QUD = 1408, κQCE = 622 → DCR 2.26 ≤ m = 2.5 — reproduced (default first row).
Preliminary calculation tool. Final design requires the full text of the referenced standard (see the sources on this page) and review by a licensed PE.