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

 Hardware                              PEDESTRIAN SAFETY


                                            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.

              ©2016 Expert Engineering Sciences, Inc.

            TEL 877-283-8518                                                                                          7
   2   3   4   5   6   7   8   9   10   11   12