Damage and failure modes of structural steel components (appendices A-G)

2005·36.7 MB·English

by  Banovic, Stephen W., Forcke, Timothy

NIST NCSTAR1-3C
Federal Building and Fire Safety Investigation of
the World Trade Center Disaster
Damage and Modes
Failure of
Components
Structural Steel
(Appendices A-G)
Stephen W. Banovic
Timothy Foecke
National Institute of Standardsand Technology • TechnologyAdministraiion • U.S. Department ofCoi

Appendix A
Examples of Perimeter Panel Floor Truss Connectors
The floortrusses were attached to the perimeterpanels at the interior intersection ofthe columns and
spandrels by different t\pes ofconnectors. The following appendix displays photographic examples,
taken by National Institute ofStandards and Technology (NIST), ofthese types ofconnectors as observed
on the recovered panels.
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AppendixA
Figure Alb: Type A floor truss connector
Figure A-1. Type A Floor Truss Connector (primary truss seat).
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Examples ofPerimeterPanelFloorTruss Connectors
Figure Aid: Type A floor truss connector
Figure A-1. Type A Floor Truss Connector (primary truss seat) (cont.).
NISTNCSTAR 1-3C. WTC Investigation 289
AppendixA
Connection ClO-CIT
Stiffener plate
Figure A2a: Type B floor truss connector
No gusset plate for damper unit
Horizontal plate
for intermediate
support angles
Welded gusset plate
with backing bar
Figure A2b: Type B floor truss connector
Figure A-2. Type B Floor Truss Connector (intermediate deck support angles).
290 NISTNCSTAR 1-3C, WTCInvestigation
Examples ofPerimeterPanelFloor Truss Connectors
Connection N8-C2T
Diagonal bracing straps attached to
gusset plate in locations indicated by
arrows
Various shapes for gusset plate
J V
Figure A3a: Type C floor truss connector
Sample M-29
Portion ofdiagonal bracing strap
Figure A3b: Type C floor truss connector
Figure A-3. Type C Floor Truss connector (anchor for diagonal bracing strap).
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AppendixA
Figure A3d: Type C floor truss connector
Figure A-3. Type C Floor Truss Connector (anchor for diagonal bracing strap) (cont.).
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Examples ofPerimeterPanelFloor Truss Connectors
Connection C25-C1B
Portion ofdiagonal bracing straps
remain attached to spandrel;
welded directly to the spandrel.
Figure A4a: Type D floor truss connector
Figure A4b: Type D floor truss connector
Figure A-4. Type D Floor Truss Connector (diagonal bracing strap welded directly
to column).
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AppendixA
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