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Reference Structural Models and Baseline Performance Analysis of the World Trade Center Towers. Federal Building and Fire Safety Investigation of the World Trade Center Disaster (NIST NCSTAR 1-2A) ***DRAFT for Public Comments***



W J. Faschan, R B. Garlock


This report establishes the baseline performance of the North and South World Trade Center Towers (WTC 1 and WTC 2) under design gravity and wind loading conditions. Baseline performance results include basic information about the towers behavior under design loading conditions. These include total and inter-story drift under wind loads, floor deflections under gravity loads, demand/capacity ratios for the primary structural components of the towers, exterior columns response (shear lag effects and presence of tensile forces), performance of connections, and resistance of the towers to shear sliding and overturning. The primary tasks that were undertaken to establish the baseline performance include the following: 1) Development of structural databases of the primary components of WTC 1 and WTC 2 towers. 2) Development of reference structural analysis models that capture the intended behavior of each of the two towers using the generated databases. 3) Development of estimates of design gravity and wind loads on the towers for implementation into the reference structural models and use in the baseline performance analysis.
National Construction Safety Team Act Reports (NIST NCSTAR) - 1-2
Report Number


World Trade Center, high rise buildings, building collapse, disasters, fire safety, fire investigations, terrorists, terrorism, structural models, columns, floors, gravity, wind load, performance evaluation, structural analysis
Created September 1, 2005, Updated February 19, 2017