RAPID: Tornado Damage to Steel Structures, Pampa, TX (November 2015)

On November 16-17, 2015, an unusual and intense late-season tornado outbreak severely damaged a group of engineered structures at the Halliburton Oilfield Services facility east of Pampa, TX, as well as several nearby center-pivot irrigation ("agricultural sprinkler") systems. The tornado that impacted the Pampa Halliburton facility was rated as EF-3 intensity, based on the damage to the metal building structures at this facility. The Halliburton facility contained multiple types of engineered structures for which structural resistances can be estimated, thereby enabling the estimation of tornado wind speeds required to cause the observed damage. Due to safety and security concerns, the facility owners prohibited access to the facility, so that it was not possible for investigators to make contact measurements or conduct close-range forensic investigations of the damaged structures. The facility owners were agreeable to the research team acquiring photographs and lidar scans from the fence line and an unmanned aerial system above the property. To collect this critical damage data, it was necessary to utilize remote-sensing platforms - including ground-based lidar and digital imaging, aerial imaging, unmanned aerial imaging (still images and video), and commercial satellite imaging.
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This data collection was funded by three collaborative NSF-RAPID Awards:
NSF Award #1623553 West Texas A&M University (Dr. J. Arn Womble and Dr. Kenneth Leitch)
NSF Award #1623542 University of Nebraska - Lincoln (Dr. Richard Wood)
NSF Award #1623752 Texas Tech University (Dr. Douglas A. Smith (TTU National Wind Institute and Dr. Elizabeth Louden (TTU School of Architecture))
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The major goals of this project are:
--Rapidly preserve perishable evidence of damage to engineered structures caused by a severe tornado, using multiple remote-sensing (i.e. non-contact) measurement and recording platforms, to facilitate future investigations of tornado-structure interactions as well as estimations of wind speeds causing these damages for use in validating or revising wind speed estimates in the Enhanced Fujita (EF) Scale of tornado intensity;
--Preserve a visual record of contents and locations in the debris field extending approximately 1 mile downwind of the Halliburton facility to facilitate future investigations of debris flight and tornado actions; and
--Archive the evidence and make it available to other researchers through the NHERI DesignSafe-ci system, to facilitate the validation of tornado loss models, debris-flight models, and further studies of tornado-structure interaction.

ACKNOWLEDGEMENTS:
Special thanks are due to the Halliburton Corporation and to Dr. Joy Pauschke and the National Science Foundation for assistance with the RAPID grants.
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