PANACHE Engineering Insights
Technical Articles & Code Guidance
In-depth guides on ASCE 7-22, HCAI/OSHPD preapprovals, anchor design, and shake table testing — written by practicing seismic engineers.
- ASCE 7-22·10 min read
ASCE 7-22 Chapter 15: Non-Building Structures — When You Leave Chapter 13 Behind
When an item is a Chapter 13 nonstructural component vs a Chapter 15 non-building structure under ASCE 7-22 — and how the design force changes between the two paths.
Read article → - Distribution Systems·11 min read
Seismic Bracing for Distribution Systems: Piping, Ductwork, Conduit, and Cable Tray under ASCE 7-22
When piping, ductwork, conduit, and cable tray require seismic bracing under ASCE 7-22 §13.6.5–13.6.7 — threshold rules, longitudinal vs transverse bracing, and the hospital I_p = 1.5 thresholds.
Read article → - ASCE 7-22·9 min read
H_f and R_μ in ASCE 7-22 §13.3: Height Amplification and Building Ductility for Nonstructural Components
How the H_f (height amplification) and R_μ (structure ductility reduction) factors in ASCE 7-22 Eq. 13.3-1 replace the old (1+2z/h) — with Tables 13.3-1 walked through and a worked rooftop example.
Read article → - Anchorage Design·10 min read
Edge Distance and Anchor Spacing in Concrete: How c_a1 and s Govern Anchor Capacity
How edge distance c_a1 and anchor spacing s drive concrete breakout and shear capacity per ACI 318-19 Chapter 17 — with the Ψ_ed factors and worked examples showing why an inch matters.
Read article → - Nonstructural Mitigation·9 min read
FEMA E-74 in Practice: A Practical Guide to Reducing Nonstructural Earthquake Damage
How to use FEMA E-74's nonstructural mitigation hierarchy, cost-effective restraints, and pre-engineered details — and where it relates to ASCE 7-22 and OSHPD requirements.
Read article → - Equipment Anchorage·10 min read
Vibration Isolators and Snubbers: Designing Equipment That Floats but Doesn't Walk Away in an Earthquake
When vibration-isolated equipment needs snubbers per ASCE 7-22 §13.6.4, how to size them for F_p, and how to handle the lift-off dynamics — including OSHPD/HCAI rules for isolated equipment.
Read article → - Equipment Anchorage·10 min read
Center of Gravity and Overturning in Equipment Anchorage: The Calculation Plan Reviewers Always Check
How to compute anchor tension and shear from F_p and F_v on tall or eccentric equipment using the center-of-gravity moment arm — with worked examples and the plan-check checklist.
Read article → - ASCE 7-22·9 min read
F_p,min and F_p,max in ASCE 7-22: When the Bounds Govern (and Why They Catch Engineers)
When the F_p,min lower bound and F_p,max upper bound from ASCE 7-22 §13.3 control the design — and how to identify the governing case on any submittal.
Read article → - ASCE 7-22·9 min read
The Importance Factor Iₚ in ASCE 7-22: When It's 1.0 vs 1.5 (and Why It Matters)
When I_p = 1.5 vs 1.0 under ASCE 7-22 §13.1.3, and how that single factor cascades through Fp, anchor design, special seismic certification, and OSP requirements.
Read article → - Electrical Equipment·10 min read
IEEE 693 vs ASCE 7-22: Which Standard Applies to Your Electrical Equipment?
When IEEE 693 governs (substation high-voltage equipment) versus when ASCE 7-22 §13.2 / AC156 governs (building electrical and switchgear) — and how to navigate dual-jurisdiction projects.
Read article → - Shake Table Testing·12 min read
ICC-ES AC156 Shake Table Testing: A Manufacturer's Guide to Special Seismic Certification
Required response spectrum (RRS), test plan, mounting, instrumentation, and pass/fail criteria for ICC-ES AC156 — the test standard that drives OSHPD OSP and ASCE 7-22 §13.2.2 special seismic certification.
Read article → - Anchorage Design·11 min read
Post-Installed vs Cast-in-Place Anchors: Choosing the Right Anchor for Seismic Anchorage
Capacity, qualification (ICC-ES ESR), and ACI 318-19 §17.10 implications of post-installed mechanical/adhesive/screw anchors vs cast-in-place headed bolts — and how to choose for seismic anchorage.
Read article → - Anchorage Design·11 min read
ACI 318-19 Chapter 17: All Anchor Limit States Explained for Seismic Design
A practical walk-through of every ACI 318-19 Chapter 17 anchor limit state — steel strength, concrete breakout, pullout, side-face blowout, pryout, and the §17.8 interaction — for seismic anchorage of nonstructural components.
Read article → - Anchorage Design·9 min read
The Ω₀ Over-Strength Factor in Anchor Design: When It Applies and Why It Matters
When the Ω₀ over-strength amplification applies to anchor design, when it does not, and how it interacts with ACI 318-19 §17.10 ductility requirements.
Read article → - Anchorage Design·9 min read
Cracked vs Uncracked Concrete in Anchor Design: When the Distinction Governs
When cracked vs uncracked concrete applies under ACI 318-19 Chapter 17, why seismic design almost always uses cracked, and how the assumption changes anchor capacity by 30–50%.
Read article → - Anchorage Design·10 min read
Anchor Bolt Tension vs Shear: How Combined Loads Govern Seismic Anchorage Design
Why combined tension–shear loading — not pure tension or pure shear — is what actually governs seismic anchor design, and how to apply the ACI 318-19 §17.8 interaction equation correctly.
Read article → - Anchorage Design·12 min read
How to Calculate Seismic Anchor Forces Under ASCE 7-22: A Step-by-Step Worked Example
Step-by-step ASCE 7-22 worked example: derive Fp, Fv, the Fp,min and Fp,max bounds, then resolve into anchor tension and shear for a 1,200 lb floor-mounted chiller anchored with four 5/8" post-installed anchors.
Read article → - HCAI / OSHPD·14 min read
HCAI PIN 68 Explained: Seismic Anchorage & Restraint for Fixed, Movable, Mobile, Countertop, Other, Interim & Temporary Equipment in California Hospitals
The complete engineer's guide to HCAI/OSHPD PIN 68 — equipment classifications, the 400 lb / 4 ft / patient care vicinity / egress triggers, the equipment schedule template, and what must be shown on construction documents.
Read article → - HCAI / OSHPD·13 min read
HCAI OSHPD OPM Preapproval Under the 2025 CBC: The Complete PIN 62 Guide for Manufacturers, Suppliers & DPORs
Everything manufacturers, suppliers, and DPORs need to know about the OSHPD Preapproval of Manufacturer's Certification (OPM) program under the 2025 CBC and ASCE 7-22 — PIN 62 policy, the new Triage Checklist, submittal package, distribution-system workflow, validity, and the 80/40/40 review timeline.
Read article → - HCAI / OSHPD·12 min read
HCAI PIN 55 (Oct 2025 Revision): What Changed for OSHPD OSP Special Seismic Certification Under the 2025 CBC
A clause-by-clause breakdown of the October 23, 2025 revision of HCAI PIN 55 — what changed for OSHPD OSP special seismic certification under the 2025 CBC and ASCE/SEI 7-22.
Read article → - HCAI / OSHPD·11 min read
OSHPD OSP Special Seismic Certification: The Complete 2022 CBC Guide for Manufacturers
Everything equipment manufacturers need to know about OSHPD/HCAI Special Seismic Certification Preapproval (OSP) under the 2022 CBC — scope, AC156 shake table testing, PIN 55 & PIN 58, submittal requirements, label, and the 60/30/30 review timeline.
Read article → - Code Updates·9 min read
ASCE 7-22 Chapter 13: What the 2025 CBC Means for HCAI OPM & OSP Preapprovals
ASCE 7-22 reshapes the nonstructural horizontal seismic force Fp with new variables (Hf, Rμ, CAR, Rpo). Here's what Preapproval and Project DPORs need to know for OPM and OSP submittals under the 2025 CBC.
Read article →