January 23, 2013
Designing Beyond the Edge
by Eve Hinman
Having a close up look at lawsuit issues that do not involve my firm is a great way to reinforce a lot of best practices about how to manage blast design projects in a relatively low pressure environment. I learned years ago that if there is a dispute related to a construction job involving blast design, blast will always be blamed for causing cost overruns. Because few people understand explosion effects on buildings, it is a fertile territory for disputes in a courtroom. Here are some of the things that I learned that relate directly to blast consultants:
- If blast testing is mentioned in any bidding or RFP documents - request, review and submit questions to clarify any ambiguities related to the test design, loads and performance.
- Alternate design options are to be clearly written as performance specifications defining the protection levels, threat or dynamic loads, and response limits.
- Document the stakeholder’s approval of the threat and level of protection prior to proceeding with developing the design.
- Make it very clear to the stakeholders what the level of protection means in terms of building damage, casualties and business disruption. They are the ones taking on the risk everyday in the building and need to understand what they are buying.
- Keep all documents and calculations related to the building design and construction until well after the construction is complete. The law requires it, and it will come in handy if ever needed.
Expert witnesses who are structural engineers generally are not familiar with blast and are often horrified by the magnitude of the load, as well as the extent of damage and injuries sustained in explosion incidents. The pressure loads are astronomical to them, and they have been trained to design for serviceability with large safety factors which are luxuries that do not exist for blast consultants. Unlike conventional structural design (i.e., gravity, seismic, or wind), blast design lacks codified requirements that dictate the development and implementation of engineered solutions.
High levels of engineering judgment are required to assess project constraints (i.e., building function, occupancy, construction type, etc.) and guide selection of appropriate measures to mitigate the ever present risk. It is this "engineering judgment" approach that often leaves blast design open for dispute and ripe for lawsuits. As expert witnesses, blast consultants serve the purpose of educating the judge about the level of risk associated with explosion incidents and provide an interpretation of the engineering judgment used to develop the design in question.
This is much like our role on the design team. Regular communication between the fragmented disciplines on the team is essential to be confident that the design and construction are progressing as intended. Proactive management as well as good communication and documentation is key to a successful project – and to reduce the chances of a costly lawsuit.