Bollard Capacity Calculator

Design safer site barriers with quick capacity checks. See demand, deflection, and utilization in seconds. Download clear outputs for supervision and documentation, daily reviews.

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Input Form

Capacity is based on a cantilever bending check.
Common structural steel values: 250–450 MPa.
Typical steel: about 200 GPa.
Load is assumed applied at the top.
Allowable = yield capacity ÷ factor.
Smaller distance increases average impact force.
Used when section type is steel pipe.
Used when section type is steel pipe.
Used when section type is solid round.
Include occupants and cargo if relevant.
5 m/s is about 18 km/h.
Saved only in the downloaded outputs.
Reset
Tip: If utilization is above 1.0, increase section strength, reduce speed, or increase stopping distance.

Example Data Table

Case Section Fy (MPa) h (m) SF Mass (kg) Speed (m/s) Stop (m) Allowable (kN) Demand (kN) Ratio
Sample A Pipe Do 168.3, t 6.4 350 1.0 1.5 1500 5.0 0.5 ~10.7 ~37.5 ~3.5
Sample B Solid D 140 350 1.0 1.5 1500 3.0 0.7 ~32.2 ~9.6 ~0.3
Example outputs are illustrative. Your calculated values depend on exact inputs.

Formula Used

  • Second moment of area (round): I = π/64 · (D^4)
  • Second moment of area (pipe): I = π/64 · (Do^4 − Di^4)
  • Section modulus: Z = I / (D/2)
  • Yield moment (simplified): My = Fy · Z
  • Top lateral force at yield: Fyield = My / h
  • Allowable lateral force: Fallow = Fyield / SF
  • Kinetic energy: KE = 0.5 · m · v^2
  • Average stopping force: Fdemand ≈ KE / s
  • Tip deflection (cantilever): δ = F · h^3 / (3EI)
  • Utilization ratio: UR = Fdemand / Fallow
This tool provides a simplified cantilever estimate. Real bollard performance depends on embedment, concrete, connection detailing, dynamic effects, and code criteria.

How to Use This Calculator

  1. Select a section type and enter its dimensions.
  2. Enter steel yield strength, height above grade, and a safety factor.
  3. Enter vehicle mass, speed, and stopping distance for the scenario.
  4. Press Calculate to view capacity, demand, and utilization.
  5. Download CSV or PDF for your records after calculation.
If utilization exceeds 1.0, consider larger sections, reduced speeds, or increased stopping distance, then re-check.

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Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.