Travis AFB Building 1365 Seismic Assessment 2019_Final.pdf

Via E-mail: brian.sassaman.1@us.af.mil

November 21, 2019

Brian L. Sassaman, GS-13, DAF Travis Installation Support Section Air Force Civil Engineer Center 550 Hickam Avenue Travis AFB CA 94535

Subject: Technical Memorandum RE: Travis Air Force Building 1365 Seismic Assessment Findings

ECM Consultants (ECM) completed the following contracted work as described in United States Air Force Solicitation Number FA4427-19-Q-0104, Seismic Upgrade Verification of Hazardous Waste Storage Facility (HWSF) at Travis Air Force Base (Travis AFB). The contracted work included reviewing documents provided by the Air Force of the original Travis Building 1365 design plans from 1962 and the TranSystems Corporation Seismic Assessment Report completed in 2005 (TranSystems 2005).

After reviewing the documents, ECM met with Air Force staff at Travis AFB on August 22, 2019 to conduct a visual inspection of the existing building components to determine if the seismic design improvements provided in the TranSystems report were implemented in the building structure.

This technical memorandum presents the findings of the visual inspection and addresses the upgrade recommendations found in the TranSystems 2005, Section IV. Assessment of Possible Risk, A.

Seismic Risks. A conceptual plan was provided in the TranSystem 2005 Report as Appendix D, and is attached to this document as Attachment 1. The following four structural upgrades were called out in the assessment and are discussed below:

1. Add New Continuous Ties and Collectors

2. Add New Steel Sheer Walls Above Existing Concrete Structure

3. Attach Concrete Roof Panels to Wall

4. Provide Miscellaneous Connection Reinforcement

ECM was able to visually inspect all elements of the building and determined that none of the above recommended improvements were present in the existing building structure. The following photographs indicate the proposed locations of Items 1-4 listed above and the lack of installed components.

Travis AFB – Building 1365 Seismic Restraint Inspection, FA442719PA136 November 2019

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Item 1 – Add New Continuous Ties and Collectors

The continuous cross ties and collectors were not installed as indicated per the diagram on Building 1365 App D Concept Plan. The continuous ties would normally consist of a tube, angle or continuous beam-column capable of resisting axial loads. (Note a beam-column is a member that is parallel the roof deck that takes axial loads. This should appear roughly centered between grid line 4 and grid line 5 in the picture below.)

Item 2 – Add New Steel Sheer Walls Above Existing Concrete Structure

The steel shear walls are not installed. If installed, it would consist of a metal panel or “x” strapping from the underside of the roof deck to the top of the concrete shear wall.

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Item 3 – Attach Concrete Roof Panels to Wall

The concrete wall panel is capable of creating seismic acceleration. If a seismic retrofit was performed, it would consist of bolts, plates, and anchorage from the wall panel to the slab and from the wall panel to the interior roof deck within each storage bay. These elements are not present.

Item 4 – Provide Miscellaneous Connection Reinforcement

The miscellaneous connections and reinforcement were not installed. These items would consist of plates, bolts, and epoxy, and would be present at the location shown in the photo below.

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Conclusion

ECM conducted a field inspection on August 22, 2019 of Building 1365 and determined that the recommended seismic improvements were not present as detailed in the report prepared by TranSystem Corporation, Seismic Assessment Report, Building 1365, Travis Air Force Base, California, December 30, 2005.

Please contact me at (559) 824-8711 with any questions or concerns.

Best regards, ECM Consultants

Don Stevens, PE Principal

Attachments: Attachment 1 – Seismic Assessment Report, Building 1365, Travis Air Force Base, California, Appendix D Seismic Upgrade Concept Plan, TranSystems Corporation, December 30, 2005.