Post-impact foundation and VSB measurements
Annex D is informative. It covers post-impact measurements of the foundation and the barrier. It adds no requirement, but it records the damage that decides whether the barrier can be returned to service.
Basis. This annex is informative. The clause number and defined terms are the standard's; the explanation is our own.
This annex is informative. It explains and illustrates; it does not create a requirement. A finding cannot rest on it alone. The normative clauses are 4 to 8 and Annex A.
What annex D asks
Annex D deals with what is measured on the foundation and the barrier after the hit. It is informative. The record covers displacement, cracking, deformation, moved fixings and the state of the ground around the base. The public preview shows the title and its place in the annex set, but not the measurement list. This record states the purpose the title establishes and does not invent a procedure. The annex is the counterpart to the penetration measurement: the penetration tells you where the vehicle went, and the foundation and barrier measurements tell you what the barrier suffered in sending it there.
Why it matters
A barrier that performed in the test may be damaged beyond reuse, or damaged in a way that is not visible from the protected side. A moved foundation, a cracked base, a stretched anchor or a deformed post changes the next impact. The site engineer needs the post-impact record to decide whether the barrier can stay in service, be repaired or be replaced. The manufacturer needs it to understand the margin in the design. The buyer needs it because the assurance statement should say not only that the barrier performed but what condition it was left in.
What good looks like
Ask the test house for the post-impact foundation and barrier measurements, with photographs and a plan of the damage. Record the repair or replacement recommendation. If the barrier is to remain in service after a real impact, have the same measurements taken on site and compare them with the test record. Do not return a damaged barrier to service on the strength of the original rating alone.
Evidence an assessor asks for
The reviewer will ask what condition the barrier was in after the test. A rating without a damage record says nothing about whether the barrier can be used again.
- Post-impact survey Displacement, cracking, deformation and fixing movement, with photographs and a plan
- Foundation record The condition of the foundation and the surrounding ground after the impact
- Service decision The repair, replacement or return-to-service decision, with the reason
- Site comparison The test damage against the damage found after a real impact, where one has occurred
Where it commonly fails
- The annex is cited as a requirement when it is informative
- The barrier is returned to service after a real impact with no post-impact survey
- The foundation movement is not measured, so the next impact is not comparable
- The repair is recorded but the effect on the rating is not assessed
What to do before the amendment publishes
Add the post-impact survey to the test report and to the site incident procedure. Record the service decision in writing.
Read across
- 4 VSB performance requirement
- 6.7 Test procedure
- B Example product and foundation drawings
- C Determination of post-impact access