Maintenance and Modifications to Structural Systems. Federal Building and Fire Safety Investigation of the World Trade Center Disaster (NIST NCSTAR 1-1C)
D A. Fanella, A T. Derecho, S K. Ghosh
This report documents maintenance and modifications that were made to the structural systems of World Trade Center (WTC) 1,2, and 7. Included are the Port Authority of New York and New Jersey (PANYNJ or Port Authority) guidelines for inspection, repair, and modifications to the structural systems of WTC 1, 2, and 7. Discussed are the guidelines that governed the inspection and strengthening of existing structural members. Also contained in this report is a summary of the structural inspection programs that were undertaken during the occupancy of WTC 1,2, and 7. Included are summaries of the facility condition survey reports that were produced for WTC 1, 2, and 7 and descriptions of the structural integrity inspection programs that were undertaken for WTC 1 and WTC 2, The significant modifications and repairs that were made to the structural systems of WTC 1, 2, and 7 from initial occupancy to September 11, 2001, are also documented. A discussion on the repairs that were made after the February 1993 bombing of WTC 1 is also included. Appendixes to this report include copies of referenced documents, including the Tenant Construction Review Manuals; the Standards for Structural Integrity Inspection of the WTC towers; and the Architectural and Structural Design Guidelines, Specifications, and Standard Details, which were all issued by the Port Authority regarding inspection, repair, and modifications to the structural systems of WTC 1, 2, and 7.
National Construction Safety Team Act Reports (NIST NCSTAR) - 1-1