Lorry crashes into and demolishes pedestrian bridge.
Lorry crashes into and demolishes pedestrian bridge.
(OP)
Apparently the M20 was blocked for 6 hours as a result of this accident.
I thought bridges over freeways were supposed to be designed to withstand this.
B.E.
I thought bridges over freeways were supposed to be designed to withstand this.
B.E.
You are judged not by what you know, but by what you can do.





RE: Lorry crashes into and demolishes pedestrian bridge.
RE: Lorry crashes into and demolishes pedestrian bridge.
Keith Cress
kcress - http://www.flaminsystems.com
RE: Lorry crashes into and demolishes pedestrian bridge.
Keith Cress
kcress - http://www.flaminsystems.com
RE: Lorry crashes into and demolishes pedestrian bridge.
Keith Cress
kcress - http://www.flaminsystems.com
RE: Lorry crashes into and demolishes pedestrian bridge.
Mike McCann, PE, SE (WA)
RE: Lorry crashes into and demolishes pedestrian bridge.
B.E.
You are judged not by what you know, but by what you can do.
RE: Lorry crashes into and demolishes pedestrian bridge.
RE: Lorry crashes into and demolishes pedestrian bridge.
TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers
RE: Lorry crashes into and demolishes pedestrian bridge.
https://www.youtube.com/watch?v=mk15ovhwrqc
Dan - Owner
http://www.Hi-TecDesigns.com
RE: Lorry crashes into and demolishes pedestrian bridge.
RE: Lorry crashes into and demolishes pedestrian bridge.
Actually Texas is one of the few places where they've addressed this issue directly. Virtually every mile of freeway has what they call 'service roads' on each side of the interstate and there are no fences or barriers along the side of the highway so it's easy to just drive off the shoulder and onto the service road. In fact, my son, who's lived in Texas for something over 16 years, jokes that when you see obvious tracks in the grass down onto the service road, he says they call that a "Texas Off-ramp".
John R. Baker, P.E. (ret)
EX-Product 'Evangelist'
Irvine, CA
Siemens PLM:
UG/NX Museum:
The secret of life is not finding someone to live with
It's finding someone you can't live without
RE: Lorry crashes into and demolishes pedestrian bridge.
And how about the concept of turning around to go back to the last exit.
But maybe if you are a trucker, and are required to only use the main highways, then there maybe no other option. Pull over and sleep it off.
I'm sure the rules are different there, and someone had a reason for the design they have.
RE: Lorry crashes into and demolishes pedestrian bridge.
Mike McCann, PE, SE (WA)
RE: Lorry crashes into and demolishes pedestrian bridge.
RE: Lorry crashes into and demolishes pedestrian bridge.
The two junctions nearest to me are ten miles apart - which is well short of the longest stretch in the UK, but still a long way to be be going "wrong way" down a major road without being really sure that you aren't going to encounter someone coming the other way at 80+ mph.
Then there's the difficulty of getting articulated vehicles off the motorway at the junction (the entry angles aren't nice and the roundabout needs to keep running the right way to cater for traffic arriving from the other direction).
With all that in mind, current strategies seek to minimise closure duration first, provide in-situ welfare for stranded travellers if that isn't possible and evacuate them from their vehicles as a last resort.
A.
RE: Lorry crashes into and demolishes pedestrian bridge.
http://digthisvegas.com/
John R. Baker, P.E. (ret)
EX-Product 'Evangelist'
Irvine, CA
Siemens PLM:
UG/NX Museum:
The secret of life is not finding someone to live with
It's finding someone you can't live without
RE: Lorry crashes into and demolishes pedestrian bridge.
The lorry with the low loader was apparently going slowly along the hard shoulder.
It has clearly passed under the gantry sign just before it.
The footbridge is a curious design with a narrowing section to allow a slope on the bridge while keeping the bottom flat and set height above the carriageway.
It would seem that the bridge section just rested on the pillar and on the midway joint.
In terms of backing up that is what happens normally. However, the location here was odd. The London bound carriageway was not far from a junction and was cleared. The southbound carriageway - the one with the bridge still standing is just beyond a complex motorway junction which made it very difficult to reverse traffic.
In the end they decided that the bridge left standing was secure and allowed traffic under it.
Motorway was closed for a day and a half.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Lorry crashes into and demolishes pedestrian bridge.
TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers
RE: Lorry crashes into and demolishes pedestrian bridge.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Lorry crashes into and demolishes pedestrian bridge.
TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers
RE: Lorry crashes into and demolishes pedestrian bridge.
Some more digging (excuse the pun) finds a bit more evidence.
This pic is the best I've seen and given that the low loader is currently crushed under the weight of the bridge so probably 0.5m lower than it would have been and an eye witness report who heard a "loud bang", it looks like the digger arm hit the side of the bridge hard enough to hit it sideways off its support on the outside of the carriageway.
Now whether the bridge was as high as it should have been or the digger was over the maximum height is going to be the key question.
I think the timing of it, the fact it hit the lorry first and the now near universal application of anti-lock brakes saved us from a multi vehicle pile up. That and the bike rider who just managed to slide under the bridge as it collapsed.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Lorry crashes into and demolishes pedestrian bridge.
TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers
RE: Lorry crashes into and demolishes pedestrian bridge.
TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers
RE: Lorry crashes into and demolishes pedestrian bridge.
I've been there, it's an absolute blast. Worth every penny.
RE: Lorry crashes into and demolishes pedestrian bridge.
That's a good view, but exaggerates it a bit as the edge of the hard shoulder is the key bit as the bridge is definitely on a slope down. The modern bridges and gantries are apparently 5.5-5.7m, but the bridges only need to be 5.03 (16 ft 6") though whether that applied to the hard shoulder when they built the motorway is not clear.
either way its quite a bit less than the gantry.
Interestingly the HSE website quotes 5.1m (!) and the new super tall trailers are up to 4.9m. Definitely scary seeing those go under some of the bridges.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Lorry crashes into and demolishes pedestrian bridge.
RE: Lorry crashes into and demolishes pedestrian bridge.
TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers
RE: Lorry crashes into and demolishes pedestrian bridge.
B.E.
You are judged not by what you know, but by what you can do.
RE: Lorry crashes into and demolishes pedestrian bridge.
TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers
RE: Lorry crashes into and demolishes pedestrian bridge.
Anyway, looking at the pictures of the pedestrian bridge, is it my imagination or does it not have much (any?) visible rebar where the break is?
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: Lorry crashes into and demolishes pedestrian bridge.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Lorry crashes into and demolishes pedestrian bridge.
RE: Lorry crashes into and demolishes pedestrian bridge.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Lorry crashes into and demolishes pedestrian bridge.
Although I'm most used to seeing it for large steel trusses over waterways -- lower collision risk there!
RE: Lorry crashes into and demolishes pedestrian bridge.
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: Lorry crashes into and demolishes pedestrian bridge.
RE: Lorry crashes into and demolishes pedestrian bridge.
To me, though I'm far from an expert, the odd thing is that there is one long cantilever over about half the span / motorway, then this beam between the end of the cantilever and what is basically a pin support. If you look back at the google streetview images I posted on 30/8 at 0843, you can fairly clearly see the beam section ends. The first half cantilever stood the test and was suspended over the motorway until it was demolished a few day later.
The design is also strange as the bridge deck is clearly on a slope down from one side to another but also narrows down as it gets to the far side.
I think someone went a bit too far trying to save on concrete and the height of stairs on the far side. This is a pedestrian bridge which then has a circular walkway on the side it was hit.
If anyone had actually been on it when it was hit it's fairly clear they would have died. how no one else was seriously injured is a minor miracle which might not happen next time.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Lorry crashes into and demolishes pedestrian bridge.
LittleInch, what you describe is pretty much the framing, using what appears to be cast-in-place section with dapped end (on the left), then the a precast drop-in (maybe should be retitled 'drop-down'
The dapped end of the precast segment, in detail:
The far right support end over the pier:
This is somewhat common framing, using precast segments, and cast-in place too. Evidently, the lateral capacity of the simple seats is questionable.