Latest Writing

Insights

Short, practical writing on concrete and steel design, lateral systems, advanced analysis, and the Python and parametric workflows that support them.

  1. Zero Mass Participation in ETABS: Why Your Modal Results Are Wrong and Where to Look

    The UX and UY columns read zero, sometimes with a period that makes no sense. The model ran, nothing crashed, and the dynamics are completely wrong. It's rarely mysterious: the table itself tells you which of four causes you've got.

    5 min read

  2. ETABS "Structure Is Unstable or Ill-Conditioned": What It Means and How to Fix It in Minutes

    The analysis stops, the log fills with capital letters, and the instinct is to click around the model hoping to spot it. That can eat an afternoon. The warning is far more informative than it looks, and there's a sequence that finds the cause in minutes.

    6 min read

  3. Why the Best Structural Engineers Are Getting Narrower, Not Broader

    The old instinct says breadth is safety. Know a bit of everything and you'll always have work. It made sense once. Now it puts you exactly where the automation is landing, and the engineers pulling ahead are going deliberately narrow.

    5 min read

  4. P-Delta Won't Run in ETABS: What's Actually Wrong and How to Fix It

    The model runs perfectly. You switch on P-Delta and everything stops. P-Delta almost never fails on its own: the model has a real problem linear analysis was tolerating, and the iteration is the first thing honest enough to refuse.

    5 min read

  5. The Rise of the "Prompt Engineer" in Structural Offices, and Why It's a Trap

    There's a new kind of office reputation: the person who's very good at getting AI to produce things. They look like the future. Prompt fluency and engineering competence are not the same thing, and confusing them is a trap.

    5 min read

  6. The Engineer's Liability Doesn't End at Handover

    The drawings are stamped, the client is happy, the file goes to archive. Psychologically the work is over. Legally and professionally it is not, and the gap is where engineers get a nasty surprise years later.

    5 min read

  7. Diaphragm Assignment in ETABS: The Mistake That Quietly Drops Your Seismic Mass

    Miss a diaphragm on a floor, or assign it to the wrong thing, and nothing complains. The model runs, the seismic loads generate, the results look complete. Part of the building's mass has quietly stopped participating, and the accidental torsion on that floor has disappeared.

    5 min read

  8. Importance Level: The One Decision That Quietly Sets Your Entire Load Regime

    It's a single classification you make near the start, often almost administratively. It silently scales every wind and seismic load the structure is designed for, and the error is baked in before you draw a member.

    6 min read

  9. Stiffness Modifiers in ETABS: Why One Uniform Value Corrupts Your Load Path

    Pick one number, often 0.35, and apply it to everything. It feels consistent. It's actually one of the quieter ways to get a load path wrong, because the point of cracked-section modifiers is that different elements crack differently.

    5 min read

  10. Coupling Beams: The Most Abused Element in Tall-Building Design

    The coupling beam is small, awkward, and sits in the way of the architecture. It's also the element that decides how your coupled-wall system actually behaves, and it gets modelled wrong more often than almost anything else in a tall building.

    6 min read

  11. The Technical Interview Questions That Actually Reveal a Structural Engineer

    Most technical interviews test whether someone memorised the right facts. The questions that actually tell you who can engineer are the ones with no clean answer — where you're listening to the reasoning, not the result.

    6 min read

  12. What Separates a Strong Structural Graduate From a Weak One in the First Two Years

    It's almost never raw intelligence or grades. The graduates who pull ahead in the first two years do a handful of specific things — and most of them have nothing to do with how much they already know.

    6 min read

  13. "The Software Said So" Was Never an Engineering Justification

    The model gave a number, the number went in the report, and nobody asked whether it was right. That was a problem before AI. It's a bigger one now.

    5 min read

  14. The Skills Worth Building as a Structural Engineer When AI Can Do the Rest

    AI is getting good at the parts of engineering that are easy to write down. The career-defining skills are the ones it can't — and they're not the ones most engineers are investing in.

    6 min read

  15. What the CPEng Assessment Actually Looks For — and What Candidates Submit Instead

    Most CPEng submissions fail on the same gap: the candidate describes what they did, when the assessment is asking them to demonstrate the competency behind it. Those are different documents.

    6 min read

  16. Accidental Torsion: The Load Case Your Symmetric Building Still Needs

    Your plan is symmetric, the centre of mass sits on the centre of rigidity, so torsion is zero — right? AS 1170.4 disagrees, and the eccentricity it makes you carry lands hardest on the corner elements you were least worried about.

    8 min read

  17. The Shear Modifier Everyone Forgets: f12 on Walls in ETABS

    Most engineers diligently crack their walls for bending and leave the shear stiffness at full value. For squat walls, spandrels, and basement walls, that single oversight quietly distorts the entire lateral distribution.

    6 min read

  18. P-Delta in ETABS: What the Setting Actually Does, and When It Bites

    Ticking the P-delta box doesn't mean you've captured second-order effects. ETABS handles one half of the problem at the global level and leaves the other half to member design — and the gap is where people get caught.

    8 min read

  19. Construction Sequence: The Loads Your Final-Condition Model Never Sees

    Your model analyses a finished building under its design loads. The structure has to survive every stage of getting there — half-built, propped, eccentrically loaded — and some of those stages are worse than the day it opens.

    5 min read

  20. PT Slabs: The Secondary Moments That Quietly Govern Your Design

    In a continuous PT slab, the prestress doesn't just balance load — the supports fight the camber it induces, and that restraint generates moments that survive all the way to your ultimate strength check.

    5 min read

  21. Differential Column Shortening: The Movement Your Static Model Doesn't See

    Run a tall concrete building in one shot and every column lands at the right level. Real buildings don't get built in one shot — the core and the columns shorten at different rates over years, and the difference redistributes force you never designed for.

    9 min read

  22. The Capability Statement Is Dead: How AI Changes How Engineering Firms Win Work

    When AI can produce a polished capability statement, a tidy methodology, and a credible-looking proposal in minutes, those things stop being proof of anything. What's left is the part AI can't fake — and it favours the specialist.

    5 min read

  23. AI Drafts the Report. A Registered Engineer Still Owns It.

    AI can write the calc, the report, and the justification faster than you can read them. But in Australia the signature on the bottom belongs to a registered engineer who is personally accountable — and that gap is about to get sharper, not softer.

    5 min read

  24. AI Won't Replace Structural Engineers — But It Will Change What We're Paid For

    The fear is that AI takes the job. The reality is subtler: it takes the parts of the job that were never the valuable part, and leaves the engineer holding the things that always were — judgement, and accountability.

    5 min read

  25. Modal Results That Look Fine and Aren't

    The model ran, the periods came out, the building drew a nice mode shape. None of that tells you the dynamics are right. Here are the checks that catch the silent errors before they reach a design report.

    8 min read

  26. Wind or Seismic Governs — And Why the Answer Changes Up the Height

    Comparing base shears tells you almost nothing. The governing action flips between shear, overturning, and drift — and between wind and seismic — at different levels of the same building. Here's how to read it.

    8 min read

  27. Cracked Section Properties in ETABS — What Most Engineers Get Wrong

    Applying 0.7 to all columns and 0.35 to all walls and moving on is the most common stiffness-modifier mistake I see — and the one with the biggest downstream consequences.

    8 min read

  28. Load Paths: The Concept That Separates Engineers From Software Operators

    Anyone can run the model. The engineer who can trace every force from where it lands to where it grounds — by hand, before the model — is the one who catches what the model hides.

    5 min read

  29. AI Will Make You Faster. It Won't Make You a Structural Engineer.

    AI can hand a graduate a load take-down, a draft calc, and a plausible answer in seconds. The danger isn't that it's wrong. It's that the struggle it removes is the exact struggle that used to build judgement.

    5 min read

  30. Setting Up a Lateral Stability Workflow That Actually Holds Up

    Most lateral systems fail in review for the same reason — the workflow skipped straight to modelling. Here's the order that catches problems before they become rework.

    7 min read