Kansas City Hyatt Regency Skywalk Collapse
http://em-jaturner.unl.edu/courses/em223/Group1/index.htm
Causes of Failure
1. Design Change of Walkway Supports
-single rod to double rod changed loading on joint
-occurred so rod wouldn’t have to be threaded
2. Did Not Meet Building Codes
-required that joints could support 151 kN
-designed so joints could support 91 kN
-one skywalk=288.9 kN; load on fourth floor joints=96 kN
3. Poor Construction
-improper wielding and connections
-inadequate building materials
Yes, I looked at the same web page myself in formulating my reply. Even though the rods did not meet the building codes at the time, a stress analysis showed that they were more than capable of handling the load.
Yes it is true that the design change did not help the cause but the final two straws were (1) the fabricated box beam in place of the drawn(?) box beam and (2) failure to place a washer or plate where the beam met up with the nut thus placing all of the stess on where the nut met up with the welded seam on the fabricated box beam. Another slide or two past the one you posted stated this as I recall.
It has been speculatted that none of these flaws by themselves would have been fatal, the combination of all the flaws led to the domino effect resulting in the collapse of the skywalks.
IIRC the fabrication of the beam was featured prominently in the KC Star during the investigation of the collapse.
Regards
alfa6 ;>}