With all of the above concerns by the time you get your beam design modified to your satisfaction, you could have specified an entirely new beam and put the money into material instead of design.
I usually keep the designs as simple as possible and use an omega of 5-6 depending on the failure...
A concrete example is attached.
Palazetto Dello Sport in Italy completed in the late 50's. Phenominal structure!http://files.engineering.com/getfile.aspx?folder=a6af6ef3-d788-4781-ad3e-762fec8c1a28&file=379487497_b0bd7be023.jpg
My anecdote:
I am great at concentrating and I actually get very distracted by handshakes. It is typical for people to give you their name just before or while shaking your hand and my concentration on the act of the handshake almost always makes what I hear (the name) never enter my...
I have a pretensioned bolted connection that always sees a rather high level of vibration where I want to use loctite thread locker to prevent bolt rotation, not safety wire. Does anyone have a clever & durable way of marking the bolts for inspection to determine whether or not there has been...
Evaluation of this bridge collapse should include bridge experts, the inspection team, as well as material experts, fatigue experts, those with knowledge of long-span truss design, geotech & foundations. A diverse team such as that can avoid tunnel vision you get when you have a very...
Prost -
How about repealing the tax decrease for the wealthiest Americans?
When much of our infrastructure was built, dams, interstates, etc. 30s to 60s the top tax bracket ranged from 62% - 92%.
Now its political
The problem with these technologies is LAWYERS. We actually tried to do this with stadiums, but we were cut off because there was too much liability involved. Your entire organization would be hung unless legislation was passed that barred the possibility of lawsuits against engineers as long...
Mtnengr - For a good example of crack propagation due to material temperature see the Hoan Bridge failure in Milwaukee. It was really cold when that happened. Three girders had fatigue cracks propagate clean through. Though it didn't fall due to catenary action in the deck. It is believed temps...
Dr. Dexter's 2001 report summary:
Bridge 9340 is a deck truss with steel multi-girder approach spans built in 1967 across the Mississippi River just east of downtown Minneapolis. The approach spans have exhibited several fatigue problems; primarily due to unanticipated out-of-plane distortion...
Some of the commentary about the event on news programs has been incorrect. The photo shown above by BIMR is of the south end of the bridge. Locks are on the south side of the river here, train tracks are on the north side. The video footage looks like it was taken from a camera that looks at...
Additionally, the visible failure or the north side of the main span seems to progress as shear failure at the within the truss at the north abutment, but the south side seems to already be moving, and ahead of the north side. It is plausble that the failure mode seen at the visible abutment...
I was down there yesterday just after it happened and it was surreal to see that there was just no bridge there where there used to be one. Unfortunately someone with our knowledge couldn't help much as it was a complete collapse. From watching the video I see an almost perfectly symmetrical...
