waross - that's a good question and I don't know. But if repairs are moving forward, I can only assume that either they can or that the locations the engineers expect the forces to transfer to can handle the additional loads. Maybe even a combo of the two.
dik - definitely could have stemmed...
I don't think uneven loading would be the case but I definitely could be wrong. This is an arch tie and should be absorbing the majority of its vertical force loads from the arch bearings. By the time live load makes it to the bearings, I suspect there has been adequate redistribution through...
Craig Neth,
If that drone is a team that specifically looking at the hangar / arch system. Sure I can see not getting that. But the fracture critical member of the structure would have been looked at closely. My experience in working with bridge inspectors doesn't cover a structure like this...
I can't help coming back to just being thankful that this bridge had enough internal redundancy to prevent a collapse. This bridge was labeled by the DOTs as Fracture Critical and that tie is likely the main reason for the designation. And this FCM has had an enormous fracture for the last few...
I agree with that assessment abusementpark. That arch looks stout and able to take a lot. But those end piers aren't very stiff in the longitudinal direction (maybe that's a good thing for today). I doubt they were analyzed for taking that thrust and wonder how they're holding up right now...
hokie66,
I agree with all you've said. And yes, the redundancy of this structure clearly saved lives this week (or whenever the fracture actually occurred).
I was referring that when the tie fractured and the arch thrust was no longer contained by that member, something had to have taken...
If that is the arch tie that was severed, I think you need to find out where that force went before you can propose a 'fix'. Is that tension force now going through the deck? Or lateral bracing system? Can the foundations handle any new longitudinal forces/deflections from the sudden thrust...
I appreciate everyone's contribution to this topic. I have some reading to do.
I did manage to find this table in BCSA that has a parallel table with FHWA's Steel Handbook. My thinking was to use category C4. While I don't have salinity in the water coming in, I likely have more dry/wet...
I appreciate anyone's help on this. I'm looking at a 20yr old bridge abutment that has steel piles inside corrugated pipes to help with expansion. Upon inspecting this abutment, I found that water had made its way into the pipes and the pile is partially submerged in water. I assume this...
I am trying to resolve a difference in lateral steel reinforcement discrepancies between ACI 318-14 and AASHTO LRFB Bridge Design Spec 8th Edition regarding the volumetric reinforcement ratio in a column.
ACI 25.7.3 gives a volumetric ratio requirement for spiral lateral reinforcement. The...
Ignacio - I really didn't want this thread to be about LBC but I'm not sure about a SR number. We let our sales rep know that we were having a number of issues with LBC and we were assigned a BrIM Support Engineer to contact directly. The negative moment issue occurred about a year or so ago...
3Fan - We're in the same boat. We've used the Conspan/RC Pier programs for a long while but we've noticed a dramatic decline in reliability recently. We've just gotten to the point where we don't trust it anymore. I'll take a look at those Iowa DOT spreadsheets. Thank you.
I've found a few...
Beyond some program stability issues, we pointed out to Bentley that the design negative moment in continuous superstructures were being miscalculated. In my specific case, the moment was undersized by approximately 30%. This was confirmed with hand calcs and an older version of Conspan. From...
I was curious what programs people use to design bridge piers/bents? My company has historically used RC Pier / LEAP but we've had issues with Bentley and this product. With this we're looking around. Thanks in advance.
I appreciate the response, I was beginning to think this was a dead thread. And no worries, I have no illusions that AASHTO will make this clear one day.
Regarding your answer, I feel that 5.10.11.4.1e is still only applicable to the entire hinge. For instance this section requires transverse...
I am curious how everyone applies the volumetric ratio for spirals in 5.7.4.6 in Seismic Zone 1 with SD1 > 0.10. In this scenario, I must meet the transverse steel requirements for a plastic hinges in 5.10.11.4.1d (which includes this equation) but between these regions, should I apply 5.7.4.6...
