Figure 4. Perimeter column/spandrel assembly and floor structure [1].
Modified by Wikipedia user. Original byː Therese P. McAllister, Fahim Sadek, John L. Gross, Jason D. Averill, Richard G. Gann. / Engineering Laboratory, National Institute of Standards and Technology (NIST)
<p>Overview of the Structural Design of World Trade Center 1, 2, and 7 Buildings. 
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