Most seismic anchorage submittals that come back with comments are not wrong. They are incomplete. The Fp is right, the anchors are adequate, and the package still gets a back-check because the reviewer cannot find the cracked-concrete assumption, or the detail on the drawing shows four anchors where the calculation used six. Below is the page-by-page anatomy of a stamped seismic anchor calculation package that clears review the first time.
1. Stamped cover sheet
Project identification, the specific equipment covered, the engineer's seal and signature, license number and expiration, the issue date, and a revision block. If one package covers several units, the cover lists every tag number it certifies — a reviewer should never have to infer scope.
2. Code and reference basis
A short section naming the governing building code (for California, the current CBC), ASCE 7-22 Chapter 13 for nonstructural component seismic demand, ACI 318-19 Chapter 17 for concrete anchorage, and AISC 360 where steel supports are involved. Any ICC-ES evaluation report for post-installed anchors is cited here by number and date.
3. Site seismic coefficients
SDS, SD1, site class, risk category, and seismic design category, with the source (project structural drawings, a geotechnical report, or the USGS/ASCE hazard tool with the coordinates used). Reviewers check this first; an unsourced SDS is an immediate comment. You can sanity-check yours with our SDS and importance factor calculator.
4. Fp derivation per ASCE 7-22 Eq. 13.3-1
The horizontal seismic design force with every term shown: the component importance factor Ip, the height amplification factor Hf, the structure ductility reduction Rμ, and the component resonance and strength factors CAR and Rpo. Then the Fp,min and Fp,max bounds, and the vertical effect Ev = 0.2·SDS·W applied to the load combinations. Show the numbers, not just the result — see our Chapter 13 reference guide for each term.
5. Equipment geometry and load path
Operating weight, plan dimensions, center-of-gravity height, anchor layout with spacing and edge distances, and the substrate description (slab thickness, housekeeping pad, steel frame). This is where overturning is resolved into per-anchor tension and shear demands.
6. Anchor capacity checks — all limit states
Tension: steel strength, concrete breakout, pullout, and side-face blowout. Shear: steel strength, concrete breakout, and pryout. Then the tension-shear interaction. Cracked concrete is assumed unless an uncracked condition is justified, and the Ω0p overstrength amplification is applied to anchors in the seismic load path where Chapter 17 requires a non-ductile failure mode to be avoided.
7. Supporting structure and attachment
Where equipment sits on a frame, curb, or housekeeping pad, the package carries the load through: member checks, weld or bolt checks, and pad reinforcement or dowel checks. A calculation that stops at the anchor and ignores the frame is an incomplete load path.
8. Anchorage detail
A dimensioned detail showing anchor type, diameter, embedment, quantity, spacing, edge distance, and installation notes. This detail must match the calculation exactly. A mismatch here is the single most frequent cause of a second review cycle.
What we need from you to build it
Equipment cut sheets with weight and dimensions, the center of gravity (or enough geometry to bound it), the mounting footprint, the substrate, the site SDS and z/h, and the Ip the project assigns. With those in hand, a single-equipment stamped package typically issues in about five business days.
You can submit all of it in one pass — including drawings and specs — through our stamped calculation request form, which also shows a redacted sample of the finished deliverable.