Designs to Meet the Extremes of Tomorrow's World

Selecting a Consultant
for Blast Effects Engineering


Has the consultant been directly involved in blast testing?

No amount of analytical sophistication can substitute for the validation of design concepts via full and sub-scale blast testing. Observing the performance of concepts in such tests provides invaluable insight into the ways that blast effects manifest themselves in the behaviors of realistic building components and systems. For instance, suitable care must be devoted to the design of attachment and anchorage systems, which are very often the weak link in a system. Exposing a design to actual blast loads is by far the most effective way of demonstrating that potential problems have been excluded and that a valid and reliable design solution has been achieved. Testing is also a great aid in refining and streamlining a design concept.

Has the consultant demonstrated innovative solutions to blast problems?

A one-size-fits-all approach seldom provides the most cost-effective solution: a consultant must be willing to adapt and innovate to meet the constraints associated with projects, such as material availability, budget limitations, and access to work areas. Even if complete protection cannot be achieved within the client's budget, many times there are simple and cost-effective approaches that can greatly reduce the effect of a blast, both in terms of structural consequences and lethality. The consultant must often work with the client through this process, as blast-resistant design is quite different from the conventional design process where loads, structural resistance, and safety factors have all been standardized.

Some specific skills needed:

  • Ability to compute blast effects loads on structures.
  • Proficient skill in using access-restricted software related to the response of structures and nonstructural components subjected to blast effects loads.
  • Ability to determine whether significant structural damage occurs, as per the engineering judgment of Government.
  • Ability to accurately predict damage levels and casualties for specific events.
  • Ability to detect unbalanced elements in a design, spot vulnerabilities that can be mitigated for little cost, and communicate the relevant concerns in a clear manner, thus facilitating the building owner to address them (e.g., specifying threat levels).
  • The capacity to provide a layered plan for responding to blast threats. This may include designing against structural collapse, even for large bombs, or by minimizing casualties in events by judicious design (e.g., designing partition walls that provide debris and blast protection even though their appearance and construction methods are the same, and their cost is little more than that of standard walls).
  • Understanding how certain blast-resistant designs (that protect against lower-yield threats) can often have a more deleterious effect to the structure and occupants (if subjected to higher-yield threats), as compared to the original state of the structure had no blast resistance been employed.

Consultant Costs

Considering the large investment that a facility or building often represents to its owner and the increasing magnitude of potential risks incurred by the occupants and users thereof, the cost of hiring a true expert who can provide:
  • realistic casualty estimates as a function of building damage, and
  • blast-resistant design of structural and MEP systems
is likely to reduce potential risks by 98 to 99.9 percent, as compared to much costlier designs that may actually increase the risks.

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