After-Storm Chasers: Lessons for Oregon from Damage Assessment after Joplin Tornado
Although tragic, every natural disaster provides an opportunity to learn new lessons, identify mistakes made in the past, and implement the new knowledge in practice. The most destructive tornado to hit the continental United States in the last 60 years also provided a similar opportunity. On 22nd May, 2011 a tornado, rated 5 on Effective Fujita (EF) Scale, ripped through Southern Joplin, MO accounting for 2 billion dollars in losses and 162 casualties.
A week after the event a delegation from Dept. of Wood Science and Engineering, Oregon State University contributed to the multi University effort through of NSF and ASCE to characterize the damages to the residential structures and schools. The delegation was led by Rakesh Gupta, who has a vast experience in the damage assessment post natural disasters, and led a similar effort post Hurricane Katrina and Tuscaloosa tornado. The team members were Arijit Sinha and Kathryn Pfretszschner. The main objective of the team was:
- Reconnaissance of damages to wood frame residential structures in order to develop an EF (Enhanced Fujita tornado scale, 0 – 5) contour map for the Federal Emergency Management Agency (FEMA).
- Identifying structures of interest that are built in different decades to perform case studies. Based on common failure modes witnessed in the case studies, develop a report with suggestions for additions to current building codes for the American Society of Civil Engineers (ASCE).
Particular interests to the WSE group were:
- Inspection of connections
- Evaluating different elements in a structures and alternative material choices
- Identifying load path or the lack of it
- Identifying avenues for material reuse and diversion from land fills
This damage assessment provided an opportunity to collect perishable data on wood-frame construction which will be useful for design engineers and code officials to design safer and more resilient structure. A tornado in Oregon might be a remote possibility, but the challenges and issues identified can help us in designing better residential structures for any type lateral load such as Earthquakes. Oregon, due to its proximity to the fault line, is a seismic hotspot and as engineers the society is looking up to us to provide them with a safe domicile in case of a seismic event.