perimeter roads to traffic, hardening building 827 against increased blast-loading conditions or
accepting additional risk to the structure.
For static perimeter barriers, it is important to note that weight alone will not prevent
penetration. As described in 18.104.22.168, concrete barriers used to protect against vehicle impact should
be anchored to a concrete foundation, if the impact angle is expected to exceed 30 degrees.
Vehicle Barrier Selection Checklist. The following checklist incorporates the selection
process and the vehicle barrier design and installation requirements. Answers to the checklist
questions should be used during the selection process for both active and passive barriers.
What is the explosive threat?
What is the weight of the threat vehicle?
Is there sufficient standoff distance between the planned barrier and the protected structure?
What is the expected speed of the vehicle?
Can the speed of the vehicle be reduced?
What is the calculated kinetic energy developed by the moving vehicle?
Have all impact points along the perimeter been identified?
Have the number of access points requiring vehicle barrier installation been minimized?
What is the most cost-effective active barrier available that will absorb the kinetic energy
developed by the threat vehicle?
10. How many barriers are required at each entry point to meet throughput requirements?
11. What is the most cost-effective passive barrier that will absorb the kinetic energy developed by
the threat vehicle?
12. Will the use of esthetic barriers at some locations be necessary?
13. Is penetration into the site a factor?
14. If penetration into the site is a factor, is the standoff distance adequate after impact?
15. Will traffic flow be affected by the barrier's normal cycle rate?
16. Will the active barrier need to be activated at a rate higher than the normal rate?
17. Will the barrier be required to be normally open (allow traffic to pass) or normally closed (stop
18. If normally open (allowing traffic flow), is adequate distance available between the guard post
and the barrier to allow activation and operation of the barrier?
19. Will the barrier be subject to severe environmental conditions?
20. Do passive barriers installed along the perimeter provide equivalent protection to the active
21. Do passive barriers interfere with established clear zone requirements?
22. In case of power failure, will the barrier fail open or closed?
23. Is this a temporary or permanent installation?