Who Broke The Bridge?

[/pine]

This is going to make a very interesting case study...You can bet there are metallurgists all over chaffing at the bit to get some sample at the point of fracture...
As long as the bridge remains intact it should help expedite the investigation...

More findings of deteriorating infrastructure especially this type of issue with disaster prevented...nothing scarier than imagining going off a collapsing bridge...to get the electorate behind the infrastructure bills entering the process...

 

[Streetcar]

Interesting failure. When a structural member breaks clean right near a major connection like that, it sort of suggests cyclical loading or vibration fatigue. The ability for the member to flex and relax is constrained when you get into short range of a connection.

Many bridges of this era have problems with fatigue cracks in weld after millions of load cycles

 

[Streetcar]

This is going to make a very interesting case study...You can bet there are metallurgists all over chaffing at the bit to get some sample at the point of fracture...
As long as the bridge remains intact it should help expedite the investigation...

More findings of deteriorating infrastructure especially this type of issue with disaster prevented...nothing scarier than imagining going off a collapsing bridge...to get the electorate behind the infrastructure bills entering the process...

The material will be tested. Cracks in truss in Kentucky were found when material was harder than plan. Harder material cracked. This was in gusset plates at connections

 

[dodge man]

Weld it? I don’t think so. On the other had $100 worth of JB Weld will get that bridge open.

 

[ruffdog]

Flex Tape!!!

 

[RickB]

Longitudinal weld for length of member.
I have been the lead engineer for inspection of several bridges across Ohio river and numerous other bridges.
Cracks can grow from fraction of an inch to completely through member in hours.

A failure like that has little or nothing to do with welds perpendicular to the failure.

 

[Diggin It]

What bothers me is ... where there is one .... how many more? How many other members on that bridge are compromised in the same way? And how may other similar bridges?

 

[void777]

Right Arlyn - looks more like some type of stress fracture. The bridge is simply pulling apart. What type of construction method relies on rivets and not welds. I wonder - is this bridge old enough that welding was not available when it was constructed.

Tied arch bridge not suspension
Bolted not riveted
Failure appears to be fatigue at weld
Beam looks to have minimal rust and section loss

streetcar

the bolts are matched drilled with a matching plate on the inside streetcar you are correct I built bridges for mdot welds are too rigid.

 

[dodge man]

What bothers me is ... where there is one .... how many more? How many other members on that bridge are compromised in the same way? And how may other similar bridges?

Ask the people in Mexico that tried to catch the subway train when the bridge broke.

 

[dusty3030]

Interesting take on it that the shorter cables towards the middle stretched less creating the stress in the area the broke. Makes sense.

Expert: Hernando DeSoto Bridge design contributed to separation, fix could take up to a year

MEMPHIS, Tenn. — Even for experts who study and build bridges every day, the case of the Hernando DeSoto Bridge shutdown is raising eyebrows. “I was shocked,” said civil engineering University of M…

wreg.com