Actions in fire, robustness, and progressive collapse — Ch. 37 orientation.

Scope

CivilTech notes on structural fire behaviour and design. Not a substitute for project codes, approvals, or peer review.

Regulatory context. South African projects follow National Building Regulations, SANS 10400, and cited material standards; use this material as orientation only.

Using this page

  1. Context — Cross-check these notes with your project fire strategy and the code edition on the job.
  2. Tools — The Fire Engineering page has ISO 834 and steel-retention calculators for quick checks.
  3. Approval — Fire resistance and structural fire design remain subject to the local authority and appointed engineers.

Fire engineering — Engineering considerations

Section 9 — Actions, combinations, and system robustness beyond single-member checks.

Actions in fire

Codes define mechanical actions and thermal actions for fire limit states; partial factors differ from ambient ULS/SLS combinations.

Robustness

Alternative load paths and tying help limit disproportionate collapse if a member or connection is lost in fire.

Progressive collapse

Where required, engineers assess whether local failure can propagate; fire is one scenario among others (impact, blast, etc.).

Diagram sources

This page has no diagram assets. Text is CivilTech orientation on actions, robustness, and disproportionate collapse—align with national regulations and the structural brief.