Government facilities often require specialized design for blast loads, but some commercial buildings and municipal structures may also be deemed mission critical and need a blast-resistant design.  Are you able to determine the design blast load when given a specified charge weight?

In the March 2021 SE University session, Aldo E. McKay, PE, from Protection Engineering Consultants, presented Blast-Resistant Design of Buildings.  Aldo shared references and resources available for blast protection of buildings and reviewed the basics of modeling structural systems and components under blast loads.  He also explained the blast loading performance objectives and blast loading requirements for different market sectors.

Aldo ran through a quick example to explain the process for determining the design loads on a building when provided with the charge weight and standoff distance of a building for an engineer that may not have access to any specialized software.  This process uses charts initially developed by Kingery and Bulmash from spherical blasts in free air, and have been scaled to represent a hemispherical surface burst.  To watch Aldo explain this process, click here.

Aldo mentioned that these curves are available in ASCE 59-11 Blast Protection of Buildings which is available for purchase from ASCE.  Using the curves, Aldo was able to establish the design incident pressure and incident impulse to use for the blast design on this project.  These incident pressures can then be used to design the roof elements or side wall structural elements.  This same process can be used to determine the reflective pressure and reflective impulse. These charts can be especially useful for the engineer who does not have specialized software or just needs a quick estimate for design pressures for blast loading.