GDE collapses onto Barton Highway

This is a worry. Seven years ago a colleague who was an engineer (albeit working in an IT job for the APS) observed some really dodgy practices going on with the construction of an office building in Allara St – one he was due to move into once completed. He raised his concerns with his supervisor – and was told to shut the **** up or risk his job. He shut up. I wish I had more detail. To this day I don’t know what the faults were, but I haven managed to avoid stepping inside that particular building myself!

Best thing for Glenoch for over a year.

So that’s 7 days now, surely enough time to minutely photograph and examine the mess, can we clean it up and re-open the road please

Fall is 3% oneway so no need to speculate futher on that point a) that’s how it looks b) the beams all fell in one direction c) (and most importantly)I know some people in low places at Roads ACT who have confirmed it.

Arthur says “P-delta effects are not a feature of flexural beam design in this case, they are primarily associated with axially loaded members such as columns in large heavily loaded sway resistant frames and are not relevant.”

Why the big deltas get all the big press when the little deltas can be just as important I’ll never know (Leonhard Euler would be most unimpressed). Firstly I’d suggest that P-Delta effects are relevant to all columns depending on exactly how you want to define your delta (could cite thousands of techical articles but I won’t). For what its worth a lateral buckling failure of a beam is directly analogous to a column failure in the sense that the compression flange is esentially failing by buckling sideways. As to whether P-delta may be relevant in this case. If you consider that the delta is the offset nature of the load to the neutral axis of the steel beam then I would suggest it is (although largely from an academic perspective).

The other technical point of interest is which beam has the heaviest load? Now intuitively many are going to say that that’s easy the ones under the voids have a lighter load (hmm maybe not). If you consider for a second the fluid nature of the concrete you might think no, wait a second the void tie downs will transfer uplift away from that area so they may in fact have the heaviest load.

By the time you have slept on it you might even think that depends on the slump of the concerete or the relative time to initial set, whether it is currently being vibrated, what temperature it is at now, what temperature was it batched at, whether there are any set retarders or superplasticisers in it or indeed who the Captain of Hawthorn is this year. Fortunately there is always some ironing out of this effect by the timber joists but my point is that like most things that look dead simple, they are not necessarily as simple as they first appear.

If you have a look using Google Earth you will see that the existing bridge and immediate approaches are straight and level so there would be no, or very little need for lateral camber of the bridge. Each sweeping bend ends well before the bridge abutments are reached. Lateral camber would be unnecessary to provide ‘extra traction’ for vehicles. It appears the existing bridge is fairly level longitudinally as well. Of course the bridge road surface (hotmix) would be ‘cambered’ to achieve adequate raindfall runoff and drainage. I doubt the new bridge would be any different.

What that means is the secondary effects referred to above would be negligible or non existent. P-delta effects are not a feature of flexural beam design in this case, they are primarily associated with axially loaded members such as columns in large heavily loaded sway resistant frames and are not relevant. The beams on the GDE falsework here would be required to carry negligible axial load. The only substantial source would be (non-existent vehicle braking forces or highly restrained temperature effects, equally non-existent) and secondary effects which would normally be carried by a bracing system. Effects due to imperfections are taken into account in the Perry-Robertson based design formulae in the steel structures code and are not directly taken into account in engineering calculations. Along with residual stresses in the steel these effects are irrelevant.

While not impossible it also is very unlikeley that a designer of this falsework would need to, or be bothered with wasting time, utilising finite element analysis. Either way the modelling method is of no consequence.

The failed falsework beams all tipped over to one and the same side because they were laterally unstable. The rest followed.

Russ said

“So if I understand correctly, the middle beam would have been plumb, but beams either side out from the centre would be increasingly (slightly) out of vertical? “

Road alignment over must be a sweeping bend because the deck has a oneway fall, underside has a parallel oneway fall and the beam supporting the ones that fell over has a parallel one way fall. So all the beams all lean in one direction. Might only be 2 or 3% but you can see the varying heights of the props on the adjacent spans. Probably not all that relevant in this case but sometimes such subtleties can be the straw that gave the camel an awful heria.

Thanks for the responses Arthur and Madashell.

Madashell said :

The other interesting point is that they are leaning in sympathy with the road camber which adds a P-Delta effect to the usual buckling phenomenom lowering the load capacity still further.

So if I understand correctly, the middle beam would have been plumb, but beams either side out from the centre would be increasingly (slightly) out of vertical? What I don’t understand is where this camber derives from, given I’d have thought the underside of a bridge can be dead flat.

Or do you mean the camber being formed on the poured and screeded concrete imparts differing masses to each beam (ie. the load is heavier in the middle than the edge), causing them to respond in this manner?

Yep I’d also say Russ is right so if that was one of your lighter 760UB’s with top loading and only partial lateral restraints at the supports (look at the ones still standing)then they’d only be good for about 20% of their fully restained capacity (assuming they span 11-13m). The other interesting point is that they are leaning in sympathy with the road camber which adds a P-Delta effect to the usual buckling phenomenom lowering the load capacity still further. The buckling equations in the code are independent of these torsional effects so some poor structural engineer is no doubt sitting around rederiving the code buckling equations from first principles to account for that effect.

I know you are probably all thinking that they could just build a finite element model (like on CSI) but that’s not really the same thing as the equations are trying to account for ‘out of straightness’ and residual stresses etc. You can also throw in a modecum of biaxial bending if you want to be really pandantic I guess, but the bottom line is that the lateral restraint was not as comprehensive as it should have been so it fell down. Everyone makes mistakes but when structural engineers make them they are very public affairs so I feel for the structural engineer in this case. Lesson learned for life I am sure but a dam hard way to learn it.

BTW someone was asking if the pump had concrete in the lines and I do not know but the hopper had been cleaned out so I expect that the answer is no.

Russ said :

So the critical failure was that the I-beams were able to twist when they should have been braced to prevent this?

It looked like that to me!

The only point I would differ on is the top flange splice plates and bolts were missing from the beams I saw. Somebody above mentioned they were replaced with a weld because the plates were removed to avoid fouling with the formwork. That would be consistent with what I saw.

Just to clarify from the experts as to what *might* have happened.

From what I understand, there were a series of 760UBs (universal beams, or I beams) that spanned the gap over the road. These were there only as a temporary support for the concrete formwork, and the lengths of beam were joined with plates on the top and bottom flange and on the vertical web, bolted each side.

On top of these beams were some intermediate elements, then sheets of glossy black formply, then a criss-cross network of steel reinforcing bars along with large hollow steel tubes that would create hollow voids through the concrete span.

They began pouring concrete using that Schwing pump that seems to be marooned there, and at some point, the increasingly heavy “deck” of freshly poured concrete caused the supporting the I-beams to twist and rotate, losing their strength from the vertical part of the “I” and thus bending, collapsing the support structure and bringing everything down that was above it, including the poor workers.

So the critical failure was that the I-beams were able to twist when they should have been braced to prevent this?

Also, seeing that pump sitting there now – does anyone know whether the operator was able to flush the concrete out of the rams and piping?

Madashell said :

“I’m just wondering what empathy towards same sex couples has to do with any of this discussion, Madashell?”

Yeah I was wondering that too? Arthur brought it up so I will defer to him on that point.
I think it was part of an ideological debate on whether human rights were more important than safty ordinances or some such thing. I’m not sure there is a right answer.

I think you’ll find it was CraigT at #78 that brought it up. Nice way to derail a useful thread though

The GDE is normally a waste of time. I live in Ngunnawal and work in Woden and make the trip every morning down Northbourne Ave because it is still quicker than the GDE. The run home isn’t as quick though so I turn up Barry Drive take the GDE from the Belconnen Way onwards.

This bridge collapse hasn’t changed my run to or from home. In fact, I think the traffic is slightly better.

Being a total cynic of anything Govco in this Territory, I could well imagine a hint being dropped to the AFP to set up RAPID ‘safety checks’ on the slow moving and congested alternate routes out of Gunners.

Gungahlin Al said :

But on the traffic issues, seems MANY people had the same idea about avoiding Flemington Rd this morning. The queue in Harrison trying to get out onto Horse Park Drive took 10 minutes (no traffic lights). But after that, the Federal Hwy was a ‘normal’ crappy 35 minute run in.

I’m likely to regret this on my drive to work tomorrow…

…but can anyone tell me what all the hysteria about the traffic situation getting out of Gungahlin is? THE GDE is OPEN.

In fact, the drive in is smoother than before, since the usual logjam and backup that takes place from the merge on the Kaleen/North Lyneham side of the existing bridge has been removed (with the removal of City/Woden bound Barton Highway traffic).

This morning traffic was banked up on Gungahlin Drive from Palmerston to the lights at Mitchell (cemetery end) – i.e. it was the lights causing the backup, not some other bridge-collapse related obstruction or new flow of traffic. After that, it was the odd experience of doing 80kmph over the existing bridge, usually taken at 10-20kmph, past Kaleen and the AIS to the Belconnen Way off ramp.

Driving out of the city via the GDE in the afternoon though, well, I can’t comment. I avoided it as it’s the natural choice for those who would otherwise have gone down Northborne Ave to Barton Highway and out. Instead, I actually opted for Northbourne Ave!

Not going to pretend to any engineering expertise. But on the traffic issues, seems MANY people had the same idea about avoiding Flemington Rd this morning. The queue in Harrison trying to get out onto Horse Park Drive took 10 minutes (no traffic lights). But after that, the Federal Hwy was a ‘normal’ crappy 35 minute run in.

However, I was surprised to see all the southbound cars turning right onto Barton Hwy, because there was no signage to warn about the detour on the Federal Hwy southbound. There was a digital sign in the northbound direction though.

Can anyone report on using Flemington?

Interested to see for the second day running CT hasn’t seen fit to produce a map of alternate routes for their readers.

An episode of The Simpsons comes to mind here …
Bart: Milhouse, what happened?! You were supposed to be watching the factory!
Milhouse: I was watching. First it started to fall, then it fell.

First rule of management Mr Nohope – you are responsible for everything, and everything is your fault. I wonder how offensive he will find that statement ???

“I’m just wondering what empathy towards same sex couples has to do with any of this discussion, Madashell?”

Yeah I was wondering that too? Arthur brought it up so I will defer to him on that point.
I think it was part of an ideological debate on whether human rights were more important than safty ordinances or some such thing. I’m not sure there is a right answer.

kruse69au said :

Arthur Mackenzie wrote:
“As for blaming people I don’t think I blamed the subbies, I don’t even know who they are and couldn’t care less about them. If the CFMEU hate them then that’s not my affair. Back to 10/10”.

I know one of those injured and he is facing up to 6 months in hospital and then a further 12 months of Rehab. He has a young family and is a great bloke. He was an site to do some screeding. But you don’t know him so you dont care.

What I meant to say, but didn’t, was that I haven’t got any issue at all with the subbies, whoever they are. There was a false accusation made against me that I did. It was a bad choice of words on my part in reply. I shouldn’t have taken the bait.

To make it clear though, rest assured I don’t have a ‘don’t care’ attitude about anybody being injured at work especially when it was out of their control.

I’m just wondering what empathy towards same sex couples has to do with any of this discussion, Madashell?

Looks like things were well progressing the 7th July. Shame you can’t quite tell if all the bolts were done up from aerial photos though.

Arthur Mackenzie wrote:
“As for blaming people I don’t think I blamed the subbies, I don’t even know who they are and couldn’t care less about them. If the CFMEU hate them then that’s not my affair. Back to 10/10”.

I know one of those injured and he is facing up to 6 months in hospital and then a further 12 months of Rehab. He has a young family and is a great bloke. He was an site to do some screeding. But you dont know him so you dont care.

I was using “lateral/torsional” in an all encompassing sense but if the beams really are 760UB’s as someone suggests then the top flanges are fairly compact and we can strike one up for you and call it a purely lateral buckling failure. If they are indeed 760 UB’s then BHP hasn’t knocked them out for years so it is second hand steel which explains the extra boltholes and splice requirements. Nothing wrong with recycling mind you as long as you do it right.

On the point of not caring. Well I am not a child but I am passionate about children’s rights. I am not religous but I believe in religous freedom. I am not a female but I care very much about their rights. Certainly I am not gay but I care very much about their rights also – getting off topic I know but you are not getting that whole point back until I ring some empathy out of you.

The kids with the mechano sets to which I refer are the ones who destroyed every other toy from birth. The kids with a wild fasination for how thing break and who stack blocks to unbelievable heights performing all sorts of torcherous balancing acts. The kids who saved like demons and stole money from their sister’s piggy banks to get that mechano set. These are the kids who will for the rest of their lives look up and have their gut tell them instantly that that ain’t right. Trust those kids I tell you trust them! If they choose to become structural engineers then my friend they will be the ones you want designing your bridges because for them it is in their blood in a way that no amount of book reading or finite element modelling will ever teach.

Madashell said :

I’m gunna give Arthur McKenzie 8 out 10. I’m taking two points off one for having a crack at same sex couples who want to get married (how the hell is that any skin off our noses) and 1 for missing that the splices are not mid span but more like quarter span. I will say that the the top flange weld was a bit light on as far as I am concerned but was supposed to be in compression and only failed after the beam had rolled.

Lateral torsional bracing is clearly miles short of what was required (any kid with a mechano set could tell you that) but I hear the mistake was on the drawings so subby is not at fault. Dam shame that the unions are kicking the subby’s head in the media when the problem was not of his making. Not much justice out there at times!

Good onya Madashell,

You’ll have to remind me where I made the same-sex couple remark. I don’t recall that one. If I did then I take it back because I couldn’t care less. Until you do that puts me back at 9/10.

As for mid span vs 1/4 span, I take your point. However it doesn’t really matter much, for three reasons – a) the missing top flange plates are more significant, b) the Steel code requires a minimum splice strength wherever it occurs on the span, and c) it doesn’t appear to me to be the primary cause of failure, the welds were working after the collapse. That puts me back to 9.25/10.

As for lateral torsional buckling, you’ll understand that what I am driving at is lateral stability which is a different mode of potential failure. My assessment is the beams tipped over and would not have reached any sort of torsional buckling. They were on the ground way before that happened – and that’s what I saw on site – the beams don’t exhibit a primary torsional buckle. You might find a buckle in the flanges but that would be post failure too. Back to 9.5/10.

As for blaming people I don’t think I blamed the subbies, I don’t even know who they are and couldn’t care less about them. If the CFMEU hate them then that’s not my affair. Back to 10/10.

Be careful of what kids with meccano sets tell you, I listened to a Structural Engineers.

Thanks for reading. Your idea of giving people marks is OK, but I think it might be better concentrating on giving marks to the people involved in this current failure. Give me 0/10 if you like but don’t forget your tax dollars aren’t affected with what I get.

I’m gunna give Arthur McKenzie 8 out 10. I’m taking two points off one for having a crack at same sex couples who want to get married (how the hell is that any skin off our noses) and 1 for missing that the splices are not mid span but more like quarter span. I will say that the the top flange weld was a bit light on as far as I am concerned but was supposed to be in compression and only failed after the beam had rolled.

Lateral torsional bracing is clearly miles short of what was required (any kid with a mechano set could tell you that) but I hear the mistake was on the drawings so subby is not at fault. Dam shame that the unions are kicking the subby’s head in the media when the problem was not of his making. Not much justice out there at times!

Jivrashia said :

H1NG0 said :

the one on Belconnen way looked dodgy hanging out over the intersection over the past few weeks. It appears as though it could easily collapse

Crap… Good point.
The people who did the supporting frames for the Barton Hwy may have also done the one for Belco Way.

Could we get kiwieng’, Arthur McKenzie, and tooheyspils observation on this?

As I said before I don’t know whether it is safe or not.

In practical terms I have no reason to trust the safety management of the site while the bridge is being built so I stay away from the area. I have only ever driven under it once or twice and prefer to take an alternative route. It’s only a couple of extra minutes, just not worth taking the risk.

We drove past there on Sunday and my wife said, jokingly, theres 50 workers just standing around waiting for another collapse. We are supposed to live in a civilised society; its third-world countries that see regular building and bridge collapses.

Not a ‘skills shortage’; dreadful mis-management. Again. Are any of us safe?

H1NG0 said :

the one on Belconnen way looked dodgy hanging out over the intersection over the past few weeks. It appears as though it could easily collapse

Crap… Good point.
The people who did the supporting frames for the Barton Hwy may have also done the one for Belco Way.

Could we get kiwieng’, Arthur McKenzie, and tooheyspils observation on this?

Maybe there is not a skills shortage but a shortage of skilled people prepared to work in the construction industry.
Maybe if the injury rate was not so high skilled people could work for a longer period.

I made comments to my girlfriend that the one on Belconnen way looked dodgy hanging out over the intersection over the past few weeks. It appears as though it could easily collapse and because of this, I avoid driving underneath it. Didn’t think it would be the one on Barton that would collapse.

I smell a Mully award

tooheyspils said :

The OH&S and RTA regulators have CLOSED the existing bridge because they fear there could be more trouble from “rubber knecking”

Note this morning’s drive in to Civic via the GDE was smoother than most regular days – might help we left 20 minutes earlier than usual, and possible people were avoiding the area on the mistaken belief the existing bridge was still closed.

It is not.

However a sight/screen (still transparent enough to be seen-through) has been hastily erected to cut down the rubber-necking.

Do we know who to blame yet? Cos I wanna rage!

Mothy said :

Yep, still open and in fact used as the Barton Highway (Northbound) detour by directing traffic to Ginninderra Drive.

Thanks, Mothy!

Me no fry said :

Can someone clarify for me whether, having turned right onto the Barton Highway from the Federal Highway (at the right-hand turn opposite Downer) the left-hand turn (onto the GDE) immediately before the now-collapsed bridge is still open?

Yep, still open and in fact used as the Barton Highway (Northbound) detour by directing traffic to Ginninderra Drive.

Can someone clarify for me whether, having turned right onto the Barton Highway from the Federal Highway (at the right-hand turn opposite Downer) the left-hand turn (onto the GDE) immediately before the now-collapsed bridge is still open?

The OH&S and RTA regulators have CLOSED the existing bridge

I’m not sure what it’s like this morning, but the existing bridge was open when I went across it in both directions at 740pm and then 900pm last night (15/08).

I agree with the danger of the rubber-neckers though. There was almost an accident last night when a car turning off Gungahlin Drive, left on to Barton Highway towards the city decided to come to a complete stop to look at the damage. Luckly the car behind was doing the 40km/h limit.

I thought NZ imported their bridges from Japan?

Its obvious the collapse was caused by the Minitries of Fire calling down the wrath of God on Canberra.

Pandy said :

What are Kiwi Engineers doing stealing Aussie jobs?

Thanks for asking Pandy. Stealing is hardly the word to use. I worked on the Gungahlin drive extension in 2006 and note that the bridge we built over Belconnen Way was constructed safely. At the time there were no contractors with enough experience of Balanced Cantilever cosntruction. I believe “filling a gap” is the word you are looking for. But don’t worry, two other engineers (who are Australian) gained valuable experience from that particular project. Just to push your comment even further… Leightons are currently in NZ “stealing” jobs from NZ engineers. So it actually works both ways. =)

Thank you Tooheyspils for your account of the accident. It is fortunate that everyone is still alive and I pray for a speedy revcovery to all. And don’t worry, I am off to NZ as to build more bridges there.

Arthur McKenzie said :

The sad thing in this overconfident spin-cycle state is there are way too many disasters – implosions, hangars, sagging floor slabs in office blocks, workers falling through missing covers and manholes, bush fires, car damage from the resurfarcing in Northbourne Ave, not to mention getting killed by a speed filled AFP car chase. All very dangerous and all totally manageable and all just disasters waiting to happen.

Yeah, but we got homosexual marriages, so at least he’s getting the really important things right.

The best map of the closure I have been able to find is on 2CA’s website http://www.2ca.com.au/ not even a mention on TAMS’ website. Looking at Google maps, the best bet for those coming into Canberra on the Barton Hwy would be exit Barton Hwy onto William Slim Dr and onto one of the many ways from there towards the City. I would assume that GDE users could still go the same way as normal using the off and on ramps.

What are Kiwi Engineers doing stealing Aussie jobs?

tooheyspils said :

Hi all. Have been to the site and had a good look around
… Cheers, Tooheyspils.

Thanks for your confirmation of what I saw Tooheyspils and great to hear that everybody is alive and ‘well’.

Yep, the complete lack of lateral (sideways tipping) stability appears to be the primary defect, closely followed by the lack of top flange splice plates and bolts. If they were left off to suit the soffit formwork then that is just plain dumb. The splices would be strong enough if all the plates were bolted up, even though they don’t brace the beams.

A 760UB is a large hot-rolled section but has only small load carrying capacity if it hasn’t been stabilised properly. Both deficiencies are a massive breach of the AS/NZ Steel Structures code in terms of the lateral stability and minimum splice strength rules.

These are very basic errors.

Tetranitrate said :

That was really quite uncalled for, especially since it wasn’t criticism of ‘dem educated people’,

Lighten up. The comment “Most seem to come straight from uni to a high level jobs and don’t have a clue about building industry except what they have read in text books.” is ridiculous. It deserves a ridiculous response. Get off your soapbox and have a laugh.

Most of the welding done on this bridge was done by none accredited “tradesman”. The bridge made hardly any noise when it gave way, just a creak and thud muffled by the multitude of wet concrete.
There will be no fruitful movement on the site for most of the week whilst the mess is mulled over and wrapped in the red tape that the ACT is most famous for. The concrete truck, hard hats and other items must stay where they lay at time of collapse.

Just another example of where bureaucracy outweighs inconvenience to the public…

nhand42 said :

gazman said :

There are too many people higher up in the construction industry with no hands on building experience to foresee any accidents. Most seem to come straight from uni to a high level jobs and don’t have a clue about building industry except what they have read in text books.

Ahh yes, the inevitable “Dem fancy book-learning types don’t knows nuttin’ about buildin’. I got my edumacation from the School of Hard Knocks” comment. Why is it I can just picture you as a high-school dropout with two missing front teeth, living in a trailer, and smoking a rollie? Go on, tell us how labourers can just smell the concrete and tap on the rebar to figure out the tensile strength.

That was really quite uncalled for, especially since it wasn’t criticism of ‘dem educated people’, rather of the idea of ‘professional managers’, and management as a distinct field divorced from whatever enterprise is being managed.

It isn’t remotely unreasonable to wonder as to the ability of people with a commerce bachelor + an MBA to manage any and every kind of business despite not actually having experience or formal education in the field.
Also, it isn’t as though this was or even is always the case, particularly in professions.

gazman said :

There are too many people higher up in the construction industry with no hands on building experience to foresee any accidents. Most seem to come straight from uni to a high level jobs and don’t have a clue about building industry except what they have read in text books.

Ahh yes, the inevitable “Dem fancy book-learning types don’t knows nuttin’ about buildin’. I got my edumacation from the School of Hard Knocks” comment. Why is it I can just picture you as a high-school dropout with two missing front teeth, living in a trailer, and smoking a rollie? Go on, tell us how labourers can just smell the concrete and tap on the rebar to figure out the tensile strength.

Hi all. Have been to the site and had a good look around, from different angles. The OH&S and RTA regulators have CLOSED the existing bridge because they fear there could be more trouble from “rubber knecking” (ie. Looking at the damage, and not looking at the road, sorry caf and ooglooooos!). I have to agree with kiwiengineer, the beams did fall to the left, as you look at the bridge from the Mitchel side,which then meant everything else followed suit. There is only one of my fellow workers still in hospital, he is only there so they can monitor his condition. I still feel that the engineers who designed the “structure” were a bit out of their league, and as kiwieng’ has stated(the first bridge was done the same way) but can I just add,(I also worked on the first bridge, its getting scary now…) the Barton highway was only TWO lanes at that time, not five, as it is now. Just to clarify a few points, the beams were designed to take vertical load, however, because they are sitting at 5 degrees off vertical,over a span of 14 metres, it didn’t take much for the 8 of them to “fall over”, meaning, they had past their point of structural integrety. So just to summarize my observations and answer Ello Vera, Kiwieng, Elfrey and Authur McKenzie’s questions and statements, Yep, the beams had no lateral support, they were bolted through the joints, bottom and side but not at the top because they needed to put formwork on the top of the flange,and needed a flatter surface, those massive beams, (and they are 760 high, go see how big that is!) should of never failed, but, as gravity was already against them, they gave way. It really is great that the whole intersection was closed to prevent any other injuries but I am still seriously gutted about the whole thing, after seeing what is left this morning at 6.30am, its bloody good to be alive and well, for those who may be interested, I do have my photo’s that I may share, please contact me throught this site, just leave a note. Cheers, Tooheyspils.

outsider said :

This is one of the very unfortunate outcomes of the high risk work pace that is civil construction …

It’s only high risk work when it’s not done properly, ie to well-established, easily managed and cost-effective standards.

thatsnotme said :

And just because I haven’t seen it specifically mentioned anywhere, confirming that the existing GDE bridge over the Barton Hwy is closed. As I was driving to the tip this afternoon (‘waste management facility’, or whatever they’re called these days…frankly, I was led to believe they would no longer be required by now?) traffic was directed off the GDE before the bridge, where you can either go left down the Barton, or cross the Barton then continue up the on-ramp to get back onto the GDE. I assume the opposite is true heading towards the city on the GDE, although I didn’t come back that way so can’t confirm.

It is a different intersection set up coming back. So traffic has to turn left onto Barton Highway & either meander through Kaleen onto Baldwin Drive or Lyneham onto Ginninderra Drive & then make their way to Gungahlin Drive. Detour signs have been erected, but not everyone understands they are for the Barton Highway closure.

Northbourne Avenue & Mitchell will be a bit of a mess for the next little while. But if we want that 12 foot statue of the Great Sir John Stanhope we have to cut costs somewhere in the budget.

This is one of the very unfortunate outcomes of the high risk work pace that is civil construction.

To blame anyone at this point is nothing less than speaking out of school.

The construction industry is evolving and moving to ensure incidents like these don’t happen, but there is a long way to go. And as mentioned previously it is not about covering “arses” with safe work method statements, it’s about tackling the skills shortage that is crippling the industry. From engineers, safety inspectors, supervisors, tradesman and labourers. This will come from experience but in time, and the clients of these projects need to beware of this shortage of skills and take it into consideration when asking for projects to completed with designated time frames

The public also need to start helping with the evolution of safe work sites. I don’t think I have been through a road site were another diver is at all interested in driving at the sign posted speed. The speeds are put there to protect the workers, we can’t be in that much of a rush can we.

I hope all the people involve have a speedy recovery and all can move on and learn from this

To the unions please be proactive and not just reactive

I am sure that in the spirit of transparency, community safety and the community interest, the Chief Minister will ensure appropriate funding will be available for an audit of the tendering, procurement risk management and compliance aspects of this disaster.

After all the Stanhope government has an extensive track record in relation to community consultation and unwaivering support for the competency of his Auditor General.

Stanhope came to power because on a public project management scandal, is anyone else getting the feeling that he’ll leave it because of one too?

dannybear said :

whats up with that police ute…..looks pretty useful in the event of arresting someone

It’s part of the [a href=”http://the-riotact.com/?p=25577″>RAPID team. They were operating spot checks on Flemington Rd. As it turned out we drove past that ute moments before it headed over to the GDE site.

And just because I haven’t seen it specifically mentioned anywhere, confirming that the existing GDE bridge over the Barton Hwy is closed. As I was driving to the tip this afternoon (‘waste management facility’, or whatever they’re called these days…frankly, I was led to believe they would no longer be required by now?) traffic was directed off the GDE before the bridge, where you can either go left down the Barton, or cross the Barton then continue up the on-ramp to get back onto the GDE. I assume the opposite is true heading towards the city on the GDE, although I didn’t come back that way so can’t confirm.

Hopefully by Monday, the traffic lights have been adjusted to give priority to cross traffic, instead of the hwy…the hwy still had prioroty today, but being a Sunday wasn’t a big deal. By tomorrow though…

There are too many people higher up in the construction industry with no hands on building experience to foresee any accidents. Most seem to come straight from uni to a high level jobs and don’t have a clue about building industry except what they have read in text books.

Detour Fail as well.

There are detour signs pointing vehicles going to Yass on the Barton hwy back onto the Gungahlin drive extension . Then no signs after that telling people to turn right onto Ginnenderra drive and to head to Yass that way. I seen interstate busses turning onto Gungahlin drive and heading back towards the Glenn lock interchange and probably onto Tuggeranong.

I recall hearing that one bridge was being constructed using pre-fab section(s) built in Newcastle, but maybe it was the one across Gininderra Drive that I’m thinking of?

That is indeed the one you’re thinking of. From memory they are using the longest such sections available – at least in this country. Interesting that they’re using at least three completely different bridge construction methods along the length of the road. (Not suggesting it implies anything negative, it’s just interesting from an engineering perspective).

It’ll be interesting to see the report of al this – how much the experience in bridge-building the contractors had and whether or not they were the cheapest tender.

Could be RCH all over again – hopefully no one dies this time around.

eq2 said :

Arthur McKenzie said :

Appears the main I section bridge deck beams weren’t laterally braced against sideways movement and rotation as they should have been. And the top splice plates at midspan weren’t attached or bolted – no plates and no bolts, just bolt holes.

What this means is the beams are laterally unstable and easily tip over on their side. The bottom splices are not strong enough to hold the beams together once they’ve tipped over. So the whole lot hits the deck!

What’s your review of the bridge under construction over Belconnen Way?

That bridge is being built using a different method, explained by kiwiengineer, I think, above. It’s a much more sophisticated way of doing it, but that’s not a reason in just itself for trusting it. The sad thing in this overconfident spin-cycle state is there are way too many disasters – implosions, hangars, sagging floor slabs in office blocks, workers falling through missing covers and manholes, bush fires, car damage from the resurfarcing in Northbourne Ave, not to mention getting killed by a speed filled AFP car chase. All very dangerous and all totally manageable and all just disasters waiting to happen.

Not necessarily Mr Nohopes direct fault but a symptom of bad management. He should be setting a better pace than this regrettable rubbish instead of telling us how offended he gets.

As for Belconnen Way, I don’t know whether it’s safe or not, I haven’t looked in detail. But I avoid driving under it. Forget about a major collapse, all it takes is somebody dropping a hammer or bolt or piece of pipe accidentally on a train of cars travelling underneath. The standard of protection against this is not very good from the little bit I have seen. Stay away from it if you can while it’s being built, at least.

Can’t be bothered reading all the comments, but I assume someone’s blamed Stanhope, right?

Arthur McKenzie said :

Appears the main I section bridge deck beams weren’t laterally braced against sideways movement and rotation as they should have been. And the top splice plates at midspan weren’t attached or bolted – no plates and no bolts, just bolt holes.

What this means is the beams are laterally unstable and easily tip over on their side. The bottom splices are not strong enough to hold the beams together once they’ve tipped over. So the whole lot hits the deck!

What’s your review of the bridge under construction over Belconnen Way?

And congratulations to the ACT Ambulance Service, ACT Fire Brigade and Aust Federal Police for a quick response and handlingof the incident – suddenly having to manage 15 casualties and a rescue in a dangerous industrial environment probably would have put their resources and operational management to the test (handling this and their regular workload). Thoughts go to the hospital staff for their work on this as well.

Unfortunately was in another dimension (NSW) until late and only heard of this accident this morning. So sorry to hear that a number of workers were hurt, 1 seriously.

Form the other comments – what was traffic doing backing up? there were huge sign board each way up for ages saying the Barton Highway would be closed on both the 14th & 15th (for the bridgework) from 8-6 daily – which was a smart move anytime.

As for disruptions – we’re just going ot have to deal with it the old fashioned way like we did before the bridge to nowhere opened up (even with only 1 lane) – just leave a bit earlier and go some other way – and be patient

Supposidly the clean up will take 5 days, and the road blocks will continue til then. So I’m guessing aviod the area til at least the weekend.

Elfrey said :

“Just went and had a quick look. Appears the main I section bridge deck beams weren’t laterally braced against sideways movement and rotation as they should have been. And the top splice plates at midspan weren’t attached or bolted – no plates and no bolts, just bolt holes.”

I know the bloke who owns whats left of the concrete pump under the bridge, and apparently the bolts snapped. High tensile steel was probably too pricey.

Certainly possible, and/or that the bolts weren’t tightened properly. I got the impression the mid-span top flange splice plates weren’t even installed in the first place! You would expect at least a few still-attached mangled plates and bolts to be there but I saw none. (Keep in mind that the other flange splice plates are still there!)

It’s also not a good move to have public access under the bridge while it’s being built. That was one of the related outcomes of the Westgate Bridge Collapse Royal Commission.

Some sculpture! Maybe Mr Nohope will dedicate it as the GAE – Gungahlin Arboretum Extension.

“It’s not the mayor’s fault that the stadium collapsed”

has anything been published about using alternate routes or the timeline in which this debacle will be sorted out yet?…….

I hope all those injured make a speedy recovery.

Makes me a bit nervous driving under the bridge construction on Belconnen Way now. Might go another way from now on.

Actually sorry… The balanced cantilever was on Belconnen Way. I am sorry. The barton Highway one was also cast-insitu using a falsework system. I believe the first bridge also had problems because a farmer passing through the job with a truck overloaded with hay hit the height warning gantry.

paperboy said :

Are we sure it’s not another Stanhope-inspired piece of art… It looks a lot like the mess on the other side of the road

It’s just a bit more expensive. cool $3.3m

Cheers, Kiwiengineer.

I recall hearing that one bridge was being constructed using pre-fab section(s) built in Newcastle, but maybe it was the one across Gininderra Drive that I’m thinking of?

The first bridge was constructed by the Federal Highway Joint Venture and it was a balanced cantilever construction. The sections were poured in-situ using concrete pumps. The formwork was supported off the structure itself. It was constructed in 2006 and done with minimal impact to traffic.

Word is that it wound be cleaned up, cheaper to have it as more “ART” for the GDE.

“Just went and had a quick look. Appears the main I section bridge deck beams weren’t laterally braced against sideways movement and rotation as they should have been. And the top splice plates at midspan weren’t attached or bolted – no plates and no bolts, just bolt holes.”

I know the bloke who owns whats left of the concrete pump under the bridge, and apparently the bolts snapped. High tensile steel was probably too pricey.

Workchoices is to blame: there’s no two ways about it. I’ve seen the union ads on TV; I know what’s going on!

I feel sorry for the people who were there when it happened, and I hope they will all make full and speedy recoveries. I also feel sorry for the poor buggers who have to spend the next few days trying to clear that mess off the road.

I guess the only upside is that it’s going to be great watching Stanhope squirm about this on the news for the next few days – and then get all indignant when some difficult questions are asked.

By the way, can anyone recall if the spans of the existing bridge were pre-fab sections that were installed in two sections by cranes?

Are we sure it’s not another Stanhope-inspired piece of art… It looks a lot like the mess on the other side of the road

Yesiree, we have a top-notch building/construction approvals and inspection regime here in the ACT.

Seems no lessons learned here:

CT 18 Jan 2008

“A car parked on a street used by pedestrians was crushed under 15 tonnes of concrete and steel in a demolition accident in Belconnen yesterday.

The Construction Forestry Mining Energy Union said it had warned ACT WorkCover about the potential dangers of the wall a fortnight ago and it had been ignored”.

Don’t know if yesterday’s bridge collapse was covered by insurance or if the ACT Government will pick up the tab for reconstruction and compensation but you can bet either way, we ratepayers and taxpayers will ultimately foot the bill. Just ask Jon.

“The bridge is ooooooooout…”

Pork Hunt said :

cranky said :

A textbook demonstration of how the ACT Gov OH&S inspectors are out of their depth.

Instead of requiring reams of paper known as a safe work statements to cover their arses in cases like these, and fining builders for not including their license no. on their signs, their training obviously misses out on building/engineering practise. They have patently missed the vital flaw in the contractors paperwork.

They should be able to actively oversight the job at hand, because they have been granted all the power under the sun to interfere with the contractor’s operation.

Authority without responsibility. Bit like local Govco as a whole.

What the f%&k does this have to do with ACT Gov OH&S inspectors?

They are not nursemaids who look over your shoulder when you’re building shit!

Why would they be looking at the contractors “paperwork”???

Engineers plan shit, scaffolders/formworkers erect shit and sadly, shit has happened.

Sweet FA to do with workcover and safe work method statements when they’re pouring concrete and it goes pear shaped!

I heard there are only 2 gov ohs inspectors doing all of the construction stuff in Canberra. Its the contractors responsibility anyway – someone has stuffed something up

arescarti42 said :

I guess it was lucky that it collapsed on a Saturday at 2pm on a Saturday. It could have been much much uglier if it was weekday peak hour.

The road was closed because they were working on it… Prime example of why its a good idea to close the road, so people ain’t driving underneath it when something goes really wrong.

Most accidents, both at work and out of work, are preventable… but human beings are flawed – we make errors, take short-cuts etc etc. So the only way to truly eliminate these things would be to remove the human element – which of course is impossible. Things are improving, but they’ll never be 100%.

So shit happens… build a bridge and get over it (just don’t use this engineer)

On a side note, hope everyone is okay. I’ll be interested to find out what happens re the Barton Hwy as I am moving to Gungahlin in the next month.

Pandy said :

Just because the big smoke of Melbourne had the Westgaste Bridge collapse, Canberra has to have its own? Damn you Stanhope!

(good that no-one was killed but)

Be careful about being critical of Mr Nohope. Not so much that you’re wrong it’s just that his usual weasel word blither of ‘finding it very offensive’ and then threatening defamation is just plain boring, but ever so predictable. Let Canberra’s Biggest and Best Disaster Man have his say now that Victoria pipped him at the post with their bushfires.

“As with all the Stage 2 [GDE] bridges 6 m approach slabs will be installed behind the bridge’s abutments. This is particularly pertinent given the post construction problems encountered with settlement of the embankments within the bridge approaches.” [June 2009]

“The Galvanised SuperProps will support steel bridging beams spanning over the live [Barton Hwy] road condition. …a second supply contract … has been secured for the … 1.2 metre thick Bridge deck to a height of 5.4 metres located at Kings Avenue in Canberra.” [May 19, 2010]

Who knows how long this inquiry might take?

(PS – no fear, the quotes are in the public domain)

I too hope no one has serious injuries from this accident. Whenever I drive under these bridge extensions currently under construction, I feel slightly nervous and wonder how safe it is for motorists passing underneath the extension.

Now this has happened. What precautions are being taken to prevent the extensions falling onto oncoming traffic?! Is it fail safe?

Just went and had a quick look. Appears the main I section bridge deck beams weren’t laterally braced against sideways movement and rotation as they should have been. And the top splice plates at midspan weren’t attached or bolted – no plates and no bolts, just bolt holes.

What this means is the beams are laterally unstable and easily tip over on their side. The bottom splices are not strong enough to hold the beams together once they’ve tipped over. So the whole lot hits the deck!

A run of the mill problem easily addressed by even the most basic engineer.

The money saved by cutting corners would have been a pittance – not even enough for a couple of ambulance rides.

dipstick said :

Lots of cops at the actual site. Wish they would have deployed a few further up the Barton at the big roundabout (William Slim/Gundaroo Rd) to stop the traffic buildup heading into the city.

What, instead of dealing with people who might actually been killed or injured instead of inconvenienced?

ace666 said :

I carn’t remember so many major building site accidents in the days when unions actually had input into site safety, as opposed to a card people carry that says they are safe. Since the attack began on union activity I can recall a hanger collapse, a couple of largish concrete slabs collapsing, this bridge. How many major collapses in Canberra prior 1996?

Just as many, if not more. The money saved in paying off union officials is invested in technologies these days. Mind you the BLF just maimed people who didn’t agree with them

Just because the big smoke of Melbourne had the Westgaste Bridge collapse, Canberra has to have its own? Damn you Stanhope!

(good that no-one was killed but)

Tooheyspils… interested to hear how you went on site.

Blimey! Thankfully noone was seriously hurt.

Hectic. Would totally suck to be the chief engineer on that job right now.

Lucky no one was killed.

Thanks tooheyspils (I preferred the old silver bullets). Look forward to reading your observations.

And here is a link to some more photos taken from a different view point:

http://www.citynews.com.au/blog/images-from-the-gungahlin-drive-extension-bridge-collapse.html

cranky said :

A textbook demonstration of how the ACT Gov OH&S inspectors are out of their depth.

Instead of requiring reams of paper known as a safe work statements to cover their arses in cases like these, and fining builders for not including their license no. on their signs, their training obviously misses out on building/engineering practise. They have patently missed the vital flaw in the contractors paperwork.

They should be able to actively oversight the job at hand, because they have been granted all the power under the sun to interfere with the contractor’s operation.

Authority without responsibility. Bit like local Govco as a whole.

What the f%&k does this have to do with ACT Gov OH&S inspectors?

They are not nursemaids who look over your shoulder when you’re building shit!

Why would they be looking at the contractors “paperwork”???

Engineers plan shit, scaffolders/formworkers erect shit and sadly, shit has happened.

Sweet FA to do with workcover and safe work method statements when they’re pouring concrete and it goes pear shaped!

Whatever the cause, and hopefully there are no serious injuries, this is just another successful entry in the Katie Bender Safety Construction Awards 2010. The whole industry here is a shameful example of how engineering is NOT done. The whole GDE is a death trap over its whole length.

As a professional engineer I am ashamed of my ACT colleagues. This is not a one-off incident. It is BAD engineering NOT bad luck!

[I say hopefully, because if there are no injuries it is due to luck and not good management.]

When is the next ACT election? The next 6 months of traffic chaos getting out of Gungahlin might be enough to change a Government if enough residents are pissed off with the ACT ALP

I’ve put up a few photos I took of it here. These have a better view than ones taken from the road.:

http://www.flickr.com/photos/enzyme05/

whats up with that police ute…..looks pretty useful in the event of arresting someone

harley said :

Mr Evil said :

Yeah, of course that’s it. There were no shonky building practices when unions ruled the roost, no sireee!

whacked union rivals actually strengthen concrete. Proven fact.

Unless an arm or leg pops out the side of the still drying slab. 🙂

When I went through the Barton Highway roundabout at 2:45, there were police directing traffic, and the Barton Highway east exit was closed. There was very heavy traffic, but the police kept it flowing as well as possible.

I guess it was lucky that it collapsed on a Saturday at 2pm on a Saturday. It could have been much much uglier if it was weekday peak hour.

These events imho are becoming more common. No contractor who can afford a lawer is concerned what workcover or the courts think. On the smaller sites things probably have improved regarding oh&s.
Experienced tradesmen and labourers, who are not afaid to speak up, imo would prevent these type of incidents.
Geting dragged before the constuction industry task force for having an opinion, would over time force you to turn the other cheeck, and keep your opinions to yourself if you wanted to still work in the industry.
The results speak for themselves!

ace666 said :

How many major collapses in Canberra prior 1996?

Siverton Centre.

In the US and other places they make the bridge offsite and then place it over the span. Miminal distruption and it takes a few hours to install (not including the supports!)

Mr Evil said :

Yeah, of course that’s it. There were no shonky building practices when unions ruled the roost, no sireee!

whacked union rivals actually strengthen concrete. Proven fact.

Yeah, the Unions would never have let this happen – they were as honest as the day is long…

I worked on this bridge. Unions have nothing to do with it. We are regulated by engineers and so called experts. When will common sense be allowed to prevail. I hope all of the guys who are injured are ok. I find it hard to believe the existing carraige way is damaged, however, if it is, that may be the reason for the collapse in the first place. I can’t see if the road under the new bridge is ok or wether it failed. The so called experts said it would be fine to use the road as the base for the new bridge, meaning….”sure, go ahead, stick 1500 tonnes of weight on the road, it’ll be fine”…. makes you wonder eh? Seeing as how we have just had 40 to 50mls of rain,it has to do something to the ground wouldn’t you think? Going for a first hand look tomorrow early, I may keep you posted.

Traffic chaos for a couple of weeks? This looks like another five years worth of traffic chaos!

Lots of cops at the actual site. Wish they would have deployed a few further up the Barton at the big roundabout (William Slim/Gundaroo Rd) to stop the traffic buildup heading into the city.

A textbook demonstration of how the ACT Gov OH&S inspectors are out of their depth.

Instead of requiring reams of paper known as a safe work statements to cover their arses in cases like these, and fining builders for not including their license no. on their signs, their training obviously misses out on building/engineering practise. They have patently missed the vital flaw in the contractors paperwork.

They should be able to actively oversight the job at hand, because they have been granted all the power under the sun to interfere with the contractor’s operation.

Authority without responsibility. Bit like local Govco as a whole.

Amazing no-one was killed.

Hopefully the ACT government didn’t take shortcut and go for the cost saving method that put life at risk.

I certainly hope that everyone is ok.

This may be an inflammatory comment, especially as I know almost zero about engineering civil or otherwise, but further to ace666’s comment, yes things may go wrong, but aren’t we advanced enough as a society for these types of accidents to *never* happen?

I would have thought that in a first world country with all of the red tape and standards that have to be met by everyone involved in the process from the glint in an engineer’s eye to the cutting of the ribbon by the Chief (not to mention the sheer amount of time that it takes for a project to be completed) that the standard would be high, and by this I mean safe.

Please don’t throw the recent rain up as an excuse, weather still has an element of unpredictability so it should always be a factor in the risk assessment of a project where people’s lives are at stake.

Another (possible), “let’s pour concrete without enough support beneath the structure” incident in Canberra? Just remember kids; wet concrete weighs more than dry concrete!

ace666 said :

I carn’t remember so many major building site accidents in the days when unions actually had input into site safety, as opposed to a card people carry that says they are safe. Since the attack began on union activity I can recall a hanger collapse, a couple of largish concrete slabs collapsing, this bridge. How many major collapses in Canberra prior 1996?

Yeah, of course that’s it. There were no shonky building practices when unions ruled the roost, no sireee!

the existing duplication bridge is also believed to be unstable. I imagine the next couple of weeks traffic will be chaotic!

I carn’t remember so many major building site accidents in the days when unions actually had input into site safety, as opposed to a card people carry that says they are safe. Since the attack began on union activity I can recall a hanger collapse, a couple of largish concrete slabs collapsing, this bridge. How many major collapses in Canberra prior 1996?

Hope everyone’s OK (I guess this is exactly why they close the road when they’re doing this kind of thing!).

It sounds like the existing carriageway is also unstable as a result of whatever happened – so prepare for traffic chaos on Monday.