US Army Corps-Corpus Christi, Texas-converted
Corpus Christi, Texas
Key Team Members
John Saraceno, Structural Engineer Lisa Buntin, Structural Engineer
Description of Project
The existing structures at Corpus Christi Army Depot include 69 steel, reinforced concrete, wood and masonry buildings used for manufacturing, repair, storage, testing facilities, and office space. The steel buildings include large steel hangars for aircraft maintenance and pre-engineered steel buildings used primarily for storage. The reinforced concrete and masonry buildings include small reinforced concrete buildings used for storage and CMU buildings used for offices. The wood buildings include wood trusses in portions of Building 8 and other wood buildings used for repair and storage.
The original portion of Building 8 was constructed in 1942 and consists of four areas (Areas A, B, C, and D), which comprise 153,600 square feet of heavy wood trusses and timber columns. Area A has 33 regular trusses which span 100 ft in the east-west direction, supported between two wooden columns. Areas B, C, and D have 140 regular and cantilever trusses which span 50 ft in the east-west direction, supported by two wooden columns. Since 1942, the Army has added 34 additional areas onto the building, each with different structural framing and support systems.
Three different sizes of wood beams were tested in bending with and without CFRP. The first sample (1.375” x 5.5” x 36”) was tested with one CFRP layer in the longitudinal direction. The second sample (2.625” x 2.75” x 36”) was tested with one CFRP layer in the transverse direction. The third sample (2.75” x 5.5” x 36”) was tested with one CFRP layer in the longitudinal direction, and one layer in the transverse direction. The beams were loaded to failure, and the results were used to determine retrofit plans and specifications for the wood trusses in Building 8.
The scope of service for the structural inspections included:
- Field inspection and special feature inspections
- Inspection reports, required forms and memorandums
- Project management, document control, and QA/QC
- Develop and review retrofit plans, review and develop specifications
HBM focused on retrofit/repair schemes for the buildings that were considered most critical to the needs of the U.S. Government. The precedence of a structure was determined by the building’s use as required by the Army. Other factors affecting the prioritization of the retrofit/repair included the age of the structure and its estimated service life.
The areas in Building 8 consisting of heavy wood trusses and timber columns were analyzed using ASCE 7-05 and 7-10 to determine the stresses caused by the design wind speeds of 140 mph and 160 mph. This analysis was conducted due to the increased design wind speed of 160 mph in Corpus Christi, Texas in the updated ASCE 7-10 code.
The results from the bending tests were used to determine the increases in strength and ductility provided by the CFRP. This information was used to develop retrofit plans and specifications for the wood trusses in Building 8.