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