Page 331 - Forensic Structural Engineering Handbook
P. 331

(e)


                                        CD7.2






                            Tower 407.1    Tower 407.2     Pier 408
                            Cross-beam CD7.2 falls down, U-heads are broken off.











                            Tower 407.1    Tower 407.2     Pier 408
                                        Tower starts to fold.











                            Tower 407.1    Tower 407.2     Pier 408
                               Top portion of north tower begins to separate.
                                              (f)
                FIGURE 10.1  Riley Road interchange. (Continued) (e) Failed concrete foundation
                pad. (From John Duntemann, Wiss, Janney, Elstner Associates, Inc., Northbrook, IL.)
                (f) Possible collapse sequence of falsework at Tower 407.2. (From NBSIR 82-2593,
                October 1982.)

                                         10.20
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