Bearing, overturning, pull-out, punch-through, and reinforcement.
Close the loop between calcs and site. This page lists ULS/SLS checks, rotation/settlement limits, and punching/shear rules for crash rated bollard foundations, with detailing notes for rebar and anchors. Consider adjacent structures and misalignment tolerance tied to set-out (612) and acceptance checks (626). An inspect/test plan connects to the ITP (714) and SAT evidence (638). Include one-sentence context that naturally links upward to the parent hubs (this section and the chapter hub). Add SIRA context with a link to SIRA Bollards (UAE) when relevant. Link installation pages only if helpful: What to Expect and Installation Guide.
Important: This is a general guide. For live projects we develop a tailored
Method Statement & Risk Assessment (MS/RA) and align with authority approvals (e.g., SIRA) where in scope.
333.1 ULS/SLS checks
Check ultimate (overturning, shear, punching) and serviceability (rotation/settlement). Limits ensure the crash rated bollard still meets gap rules (232, 314).
Start with rating evidence and turn it into foundation actions. At rating-critical dependencies level, the tested system (bollard+footing) governs the design envelope. For standards terminology, note whether the report provides base moment, shear and displacement—these feed your moment quick-estimate and soil checks.
At acceptance checks (626) the array must still satisfy the clear-gap rule after deformation. Therefore verify soil/groundwater influences and include a conservative safety factor for base rotation.
| Aspect | What matters | Where to verify |
|---|---|---|
| ULS (overturning) | Resultant vs. resisting moment (soil, self-weight, passive pressure) | Foundation Moment Quick-Estimator |
| ULS (shear) | Base shear vs soil friction/keys; anchor group shear | Impact loads & foundations |
| SLS | Residual set & plumb vs effective opening | Clear-Gap Calculations |
333.2 Rotation/settlement limits
Set small-angle rotation and mm-level settlement caps. Caps protect HVM bollard clear gaps after impact (322).
Define movement limits as SLS criteria tied to deflection vs permanent set. Express base rotation as degrees and head offset at the defend line; relate both to the effective opening. For early-stage sizing, assume a linear stiffness (kθ) for the footing/soil; refine later from geotech.
Settlement caps should reflect paving interfaces and drainage falls (629). Document the survey method (plumb readings, datum stick, before/after impact) in the ITP for reproducibility.
333.3 Punching & shear
Detail shear links and studs near sockets. Prevent brittle failure that would compromise a crash rated bollard.
Local checks include punching around sockets/posts and one-way shear at critical sections. If using shallow frames or precast pockets, ensure the load path into the slab/beam is continuous; add closed stirrups or stud rails as required. Where foundation typicals use rails, provide endstops and confinement to avoid punch-through.
Verify that punching/shear capacity still exceeds demand when accounting for tolerances in socket position and cover; use robust bar diameters and spacing near the post to resist diagonal splitting.
333.4 Reinforcement detailing
Lap, hook, and confine; maintain cover (621). Detailing survives hot climates (337) and keeps HVM bollard heads aligned.
Provide a compact foundation cage with closed ties around the socket. Keep bar bends clear of the anchor group and cable penetrations (622). Respect minimum cover and use spacers that survive vibration (624). Hooks/laps should be standardised for the product family to simplify checks.
In hot climates (337), specify curing and crack control to limit early shrinkage; confirm galvanizing growth and tolerances at the head (315). Provide keepered openings and grout beds (625) so the head finishes plumb with the paving module (629).
333.5 Anchor design
Design plate/anchor groups for combined actions; verify pull-out. Anchors are rating-critical for a crash rated bollard (421).
Anchor groups resist combined tension, shear and moment from the post. Check steel strength, concrete breakout, pry-out, and group edge distances. Where possible, avoid red-zone utilities (617) that force eccentric anchoring. If chemical anchors are permitted, verify cure time vs pour programme and add proof-testing in the ITP.
For frame/rail systems, confirm end-anchorage and shallow foundation bearing—include friction keys or dowels if shear demand is high. Where approvals apply (Dubai), align with SIRA expectations for evidence of anchor capacity and witness testing.
333.6 Adjacent structure checks
Check slabs, utilities, and facades nearby (335, 234). Prevent load transfer that harms HVM bollard surroundings.
Impact loads can “find” weak links. Check nearby services, façade plinths and retaining edges for unintended load paths. Respect easements/no-go envelopes defined during utilities surveys (240–247) and keep minimum set-back from glazing per frontage protection. On duct/trench runs, verify that compaction and cover don’t compromise slab punching or bearing.
333.7 Tolerance to misalignment
Define acceptable plumb/rotation before pour (612). Tolerances preserve crash rated bollard geometry.
Set a pre-pour acceptance band for socket plumb, centreline and elevation. Use jigs/brace frames with a datum stick for repeatable checks; record all readings in 626. If the product family has an as-tested configuration dependency (421/415), state the permissible shims/adjusters explicitly to avoid downgrading performance.
After pour and curing (627), repeat plumb checks and verify projected gap along the defend line. If drift is detected, assess whether corrective works will recover the clear-gap rule.
333.8 Inspect/test plan
Embed ITP checkpoints (714): steel, cover, anchors, pour, cubes. Evidence supports HVM bollard acceptance (638).
At minimum, include hold/witness points for cage inspection, anchor placement, formwork and cover, pour/vibration, cylinder/cube sampling, grout beds/levelling, and post-cure alignment. Reference the SAT/witness procedure and add photo evidence to the photo/redline logbook. For automatic units, coordinate with loop and field-device tests (344–345).
333.9 Designer’s checklist
Provide a one-page list for calcs, details, and records (444). Checklist shortens reviews for crash rated bollard submittals (938).
Use a single-page checklist that confirms: inputs (rating string, soil), ULS/SLS results, punching/shear checks, anchor capacities, adjacent-structure review, tolerances, and ITP references. Attach the completed sheet to the evidence & documentation pack and cite it in the submission-pack guidance. Link to the moment quick-estimator (923) for transparent reviewer recalculation.
Related
External resources
- ASTM F2656 — Crash Testing of Vehicle Security Barriers
- NPSA — Hostile Vehicle Mitigation (HVM)
- BSI — Impact Test Specifications for VSB Systems
333 Design checks for Crash-Rated Bollards foundations — FAQ
What ULS and SLS checks are essential for a bollard foundation?
At ULS, verify overturning moment, base shear and local punching around the post or socket. At SLS, cap base rotation and settlement so the clear-gap remains compliant after deformation and reinstatement.
How do I set practical rotation/settlement limits?
Use certificate displacement/penetration data and deflection vs permanent set guidance to derive a small-angle rotation and a mm-level settlement cap that still preserves the effective opening in clear-gap calculations.
When are anchors rating-critical?
Where the crash test was performed with a specific baseplate/anchor group, those details are rating-critical dependencies. Match edge distances, embedment and group layout; add proof-tests in the ITP.
What goes into a one-page designer’s checklist?
Inputs (rating string, soil), ULS/SLS results, punching/shear checks, anchor capacities, adjacent-structure review, tolerances, and ITP/SAT references—file it with your evidence & documentation and submission pack.