An FHWA research project to assess the performance and design of steel gusset plate
connections facilitated actions that addressed one of the final NTSB recommendations.
He covers the design and analysis for smart partially restrained concrete-filled tube connections, both end plate and T-stub types; for bolted connections, including component models for recentering bolted connections; and for gusset plate
, recentering slit damper and smart damping smart connections.
--beam and column web (2), gusset plate
(3) in bearing;
Similarly, the I-35W bridge failure in Minneapolis in 2007 was a fracture-critical situation, in which a gusset plate
was too thin, owing to a design flaw.
However, the I-35W investigation also found that the "corrosion documented on the gusset plates
" had been "overlooked or underestimated by bridge inspectors using visual inspection methods," and the NTSB made safety recommendations asking the FHWA to require more in-depth inspections to detect gusset plate
An investigation by the National Transportation Safety Board assisted by the FHWA determined that the immediate culprit was a failed gusset plate
, one of the flat, heavy pieces of steel that are bolted in pairs to join the ends of the steel members that form the bridge truss, according to Justin Ocel, an FHWA engineer.
" After the collapse, the UK- based company said it feels that the orientation of the gusset plate
were in wrong plane.
The steel connector casting developed by Cast Connex consists of a solid round section transitioning into two flat plates that are bolted to a gusset plate
. Bolt attachment to a single gusset plate
accommodates simple fabrication, construction and site erection.
Writing in Firehouse magazine, John Norman, a captain with the Fire Department of New York, cautions that "buildings which were constructed using plywood I-beams, 2x4 gusset plate
trusses, or the composite steel and wood trusses have all been proven to collapse [within] as little as five minutes of fire exposure."
In this connection, braces and beams were connected to a vertical gusset plate
that penetrates to the circular CFT column and forces transfer solely through friction between concrete and steel and bearing at the bottom of the plate.
A bent gusset plate
was photographed and filed in 2003.