Page 7 - Electrical Conduit, Elbows, Couplings, and Nipples | Allied Tube & Conduit

 Hardware PEDESTRIAN SAFETY

CALCULATOR

¹ The Yield Speed is based upon an energy analysis that assumes that the ability of a bollard to resist
the movement of an impacting vehicle is limited by the yield strength of the material from which it is
constructed. This assumption provides a conservative analysis, since a bollard’s ability to resist an
impact is actually limited by its ultimate strength. The Yield Speed has been estimated from an energy
analysis that includes considerations for the material properties of various grades of steel pipe and
cured concrete under static loads, but does not take into account the impulse force of an actual vehicle
collision. The Yield Speed should not be interpreted as the true limit of a bollard’s performance, or an
indication of the speed at which a vehicle could impact a bollard and be stopped.

² The Speed Rating is based upon the same analysis as is the Yield Speed, with the additional
assumption that the steel will only provide 66% of its specified yield strength under an impact
condition. This assumption provides a safety factor to account for the differences between static loads
and vehicle impacts, and to ensure that the actual performance of the bollard material will always
exceed the Speed Rating.

This worksheet is intended to illustrate the relative material strength of various sizes of steel
pipe bollards for planning purposes only. It is not intended to be a design tool, or provide engineered solutions to your storefront protection
requirements. Bollard systems for any specific site must be part of a complete design that takes into consideration the site’s land use, local
geotechnical data, hydrologic data, traffic patterns, existing and proposed utilities, elevation differentials (e.g. curbs), and other important
features that might not be apparent.

All of the calculations in this worksheet assume that the bollard(s) are embedded in a foundation that can withstand the internal pressure induced
by the applied loads, and is adequate to counter the applied force and over-turning moment generated by this force without excessive movement.
If you intend to install a bollard system as a protective device for your storefront or other location, it is critical that the foundation(s) for each bollard
system be designed in accordance with the expected loads, local building codes, and site-specific data. Bollard foundations must be specifically
engineered as a part of the overall design or retrofit of a facility. Expert Engineering Sciences can provide civil engineering services for the
installation of bollards at storefronts, building sites, and for other permanent and temporary projects.

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