Design failure mostly.
"An examination carried out by theFederal Highway Administration
<https://en.wikipedia.org/wiki/Federal_Highway_Administration>discovered
faults in the design of the bridge, which overestimated the strength of
the bridge in the region which failed, and underestimated the load it
would be expected to carry.^[4]
<https://en.wikipedia.org/wiki/Florida_International_University_pedestrian_bridge_collapse#cite_note-NTSB-2ndUpdate-4>
TheNational Transportation Safety Board
<https://en.wikipedia.org/wiki/National_Transportation_Safety_Board>issued
a "News Release"^[5]
<https://en.wikipedia.org/wiki/Florida_International_University_pedestrian_bridge_collapse#cite_note-NTBS_Release-5>
which said,"that load and capacity calculation errors made by FIGG
Bridge Engineers, Inc., are the probable cause of the fatal ... bridge
collapse in Miami ..." The same day the NTSB released a "synopsis"^[note
1]
<https://en.wikipedia.org/wiki/Florida_International_University_pedestrian_bridge_collapse#cite_note-6>
of its final report, which stated
... that the probable cause of the Florida International University
(FIU) pedestrian bridge collapse was the load and capacity
calculation errors made by FIGG Bridge Engineers, Inc., (FIGG) in
its design of the main span truss member 11/12 nodal region and
connection to the bridge deck. Contributing to the collapse was the
inadequate peer review performed by Louis Berger, which failed to
detect the calculation errors in the bridge design. Further
contributing to the collapse was the failure of the FIGG engineer of
record to identify the significance of the structural cracking
observed in this node before the collapse and to obtain an
independent peer review of the remedial plan to address the
cracking. Contributing to the severity of the collapse outcome was
the failure of MCM; FIGG; Bolton, Perez and Associates Consulting
Engineers; FIU; and the Florida Department of Transportation to
cease bridge work when the structure cracking reached unacceptable
levels and to take appropriate action to close SW 8th Street as
necessary to protect public safety.^[6]
<https://en.wikipedia.org/wiki/Florida_International_University_pedestrian_bridge_collapse#cite_note-NTBS_PublicMeeting-7>
/The New York Times
<https://en.wikipedia.org/wiki/The_New_York_Times>/concluded that "the
chief probable cause" was "the design by FIGG Bridge Engineers", but
that "every company, institution and agency involved in the project was
partly to blame for the bridge collapse"
"As the post-tensioning operation by the VSL company was being carried
out on bridge diagonal member support #11, the bottom joint (which
contains the anchor nut for the post-tensioning rod) apparently failed
explosively, causing the bridge to collapse. Currently, it remains
unknown why the joint may have failed, although post-tensioning remains
a likely contributor.^"
On 31/10/2019 3:42 PM, G Mann via Mercedes wrote:
I believe I recall the postmortem on the event found a combination of lack
of spec post tension and failure to allow proper cure time for the
concrete.
Do not recall for sure, but my memory says, concrete was also sub spec for
strength in the mix.
Rush job, with failure on film as I recall..
On Thu, Oct 31, 2019 at 1:29 PM MG via Mercedes <mercedes@okiebenz.com>
wrote:
I believe it was incorrect tension.
OK Don via Mercedes wrote:
The presence, or lack of them caused the collapse?
On Thu, Oct 31, 2019 at 2:01 PM Randy Bennell via Mercedes <
mercedes@okiebenz.com> wrote:
Post tensioning cables.
-D
Is that not what caused the problem with that pedestrian bridge to some
university down your way, that collapsed?
Randy
_______________________________________
http://www.okiebenz.com
To search list archives http://www.okiebenz.com/archive/
To Unsubscribe or change delivery options go to:
http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
_______________________________________
http://www.okiebenz.com
To search list archives http://www.okiebenz.com/archive/
To Unsubscribe or change delivery options go to:
http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
_______________________________________
http://www.okiebenz.com
To search list archives http://www.okiebenz.com/archive/
To Unsubscribe or change delivery options go to:
http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
