Opal Tower - Sydney Australia 28

[CivilEngAus]

https://www.news.com.au/national/ns...s/news-story/dad28af4aad5ff11cf968102635824f9

https://www.smh.com.au/national/nsw...ns-building-may-collapse-20181224-p50o4b.html

This could be an interesting and developing story in Sydney Australia. A 34 storey near new residential apartment tower in Sydney has been evacuated this afternoon over fears it is in structural distress with cracking noises heard during the day and one or more cracks developing; emergency services are treating it as a major incident.

Given we already have some of the toughest building codes in the world (although little to no registration requirements for engineers) it will be interesting to see how this plays out and what the crack(s) looks like to cause such a major emergency response.

 

[Agent666]

In the photos pasted by CivilEngAus, assuming its the same location as the photo I posted(?) it looks like some of the concrete has been removed to expose the reinforcement. However to me I'm not sure what I'm looking at, a beam/column/wall, reinforcement that is exposed doesn't appear to be consistent with what I would be expecting for either a beam/column/wall.

What experience/seniority have the people making these mistakes?

Everyone makes mistakes, from graduates to the most experienced engineers. Some of the most significant issues I've exposed over the years are from graduates, and people with several decades experience, there is no magic number here. It can happen on the smallest and simplest of jobs, or on the most complex and large jobs. In the worst cases I've driven complete redesigns of the structure causing months and months of delays, it's not really very fun being a peer reviewer, no one ever thanks you for discovering all their errors. You cop a lot of flack, but you have to stick to your guns and stand up for what you believe in.

Certainly sometimes there are repeat offenders, both individuals and companies. To some degree its down to the level of internal verification (and experience of those doing this internal review) or the lack of it in most cases. Things taught incorrectly 'on the job' by more experienced engineers tend to be adopted by less experienced engineers without a second thought and passed on further afield. You challenge this and you get the old this is the way we have always done it by some companies, sometimes it can be quite hard to convince people when you are changing cumulative decades of poor or inherited understanding. In the past on occasion I've had to go all the way to those that wrote particular code requirements to get them to personally explain/confirm the requirement to the designer in their own words. Sometimes the answer I hear back from the designer is 'well why didn't they say that in the code'... so code writers with all their collective knowledge could perhaps do a better job communicating the requirements considering some of the readers don't have their background knowledge.

It's interesting how people react to being proved incorrect or challenged on their understanding. For example some people are very receptive, and acknowledge the error once they have that 'lightbulb' moment and interpret what you are saying, others react defensively by producing 50 pages of calculations to refine their analysis to prove that extra bolt I asked for to get it to work for example doesn't in fact need to be added along with throwing you under the bus as being picky/pedentic, etc to all that will listen (Project managers/client/etc). Any delays are mostly due to the original designer getting it wrong, not attributed to the peer reviewer discovering too many errors......

I have more respect for those that listen and take on board what I am saying and make any changes required or respond to the queries to address the root cause, as opposed to those who play the numbers and refuse to accept that they might have made an error.

 

[Skogsgurra]

We have that in the 'lectric, too.

My last case, which is likely going all the way to the court-room, is about "old wisdom" and new reality. The old and common wisdom is that bearing problems occur only in larger electric motors while the new reality is that problems (as a result of energy-efficient motors and frequency inverters with very fast switches) now can be seen in motors from FHP up to tens of megawatts.

I think that the building/structural community sees changes over a somewhat longer time than they happen in the drives area where "revolutions" happen almost every second year. And the gain is not always obvious. Rather the opposite.

Gunnar Englund

http://www.gke.org

--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.

 

[Agent666]

From a recent news article (5th January), hopefully some more info/answers are coming.

Professors Hoffman and Carter expect to release a more comprehensive update by the end of next week.

 

[human909]

From a recent news article (5th January), hopefully some more info/answers are coming.

I won't hold my breath but I will be keeping an eye out.

I would be quite surprised if a "comprehensive" report was at all publically available, let alone at the end of next week. My reasons are due to my cynical nature regarding the transparency of Australia's building industry and the fact that this independent investigation is a couple of academics hastily employed for political reasons as much as investigatory reasons. (I have no reason to question the competency of the independent investigators, but the suggestion that a comprehensive report can be completed in a couple of weeks seems a little ambitious.)


Meanwhile the media is still having a field day on this topic. Residents are complaining about having their apartments ripped apart and their belongs pile in corners. Which is perfectly acceptable giving the structural concerns. However the optics are terrible. First it was evacuation. Then it was safe. Then it was evacuation again for a 'short period'. At every stage those running the show (Ecove, Icon) have been at pains to talk down the issues. But that has made things worse. If they had been upfront then they could have readily given residents the opportunity to remove their personal possessions themselves and avoided all this.

Here is hoping all this mess is a big wake up call to the industry. Going back to a post from 2 weeks ago.

The Australian newspaper has reported that the NSW government will conduct an inquiry into the problem with this building. Based on many government inquiries in Australia, this could expand to be bigger than Ben Hur. Maybe that is a good thing.

I agree. Though I'd hope for something federally led rather than state led. And given the lame duck nature of the current NSW government I wouldn't hold my breath from action from them.

 

[hokie66]

"Lame duck" would seem to be a good description for the federal government as well. And with union controlled Labor governments, it won't be just holding your breath, you will have to hold your nose.

 

[rscassar]

There was a statement that came thru on Linkenin yesterday:

Bonacci wish to highlight that the Sydney Morning Herald have incorrectly identified us as the structural engineer for Opal Tower at Sydney Olympic Park. The SMH has since published a retraction. Bonacci did not design or certify the structure of Opal Tower.

Our thoughts go out to the residents and all those involved over this difficult time and hope for a speedy resolution.

 

[david256]

Here's a list of units which have had propping and inspections.

An image of unit 1005 without the room number blanked out.

 

[Agent666]

If someone has time to highlight on the arch plans where the propping (and inspections) are, it might offer some insight if the propping is local to the areas previously highlighted, or if there is concerns in other areas that might have similar detailing to the area that is known to have failed?

 

[hokie66]

I think the speculation in this thread could be better focused if we had some structural drawings to digest. From what I have seen, there is not even a good description available of the structural system.

 

[Agent666]

Totally agree, with some drawings
we'll know a whole lot more. Hopefully some drawings will be included with the initial report that's been promised. Though if there has been construction changes due to the design/build nature of the contract there might not be a good record of what was built!

 

[StructEng23]

Pretty doubtful that the structural engineering drawings will be made available.

I have heard that even the engineers investigating are having difficulties getting the drawings from the builder and the consulting engineer.

 

[hokie66]

A pity. This is in stark contrast to the situation with the recent pedestrian bridge collapse in Miami. Perhaps the designer and builder would rather hear wild speculation than learned opinion.

 

[StructEng23]

The difference between this and the Miami bridge though is that the bridge drawings were made public prior to the collapse, so they were already in the public space.

No engineer in Australia would like their drawings made available to the public, particularly after a collapse!

 

[david256]

Agent666 here's the approximate location of propping in unit 301 and 302.

101,102 and 201,202 were also propped so I would assume they also follow grid line 15.

The partition wall between units 301 and 302 has been removed between B1.

Approximate prop location marked in red along grid line 15, same plans floors 1-3. The giprock along grid line 13 has been removed on the inside of 301.

Level 4 plan showing the approximate location of propping in unit 301 and 302 along grid line 15.

https://www.heraldsun.com.au/news/n...-tower/video/010f53a289e9e6488e83d7f90eed806d

Link to video of room 301.

Thanks goes to the member of another forum.

 

[hokie66]

StructEng23,
Understood. But there is now a governmentally funded investigation, so the drawings will eventually become public. There is no point in delaying the inevitable.

 

[hokie66]

We will have to wait and see on this promised report. But neither of the two professors who have been appointed by the NSW government to investigate are practicing structural engineers. One is a geotechnical engineer, the other I think mostly a materials specialist. Hopefully, they have help with understanding this apparently complex structure.

 

[jhardy1]

Professor Mark Hoffmann is the Dean of Engineering at the University of New South wales, and his areas of specific expertise are listed as including:
Structural integrity; fracture and failure analysis; ... ; structural modelling and life prediction ...

https://research.unsw.edu.au/people/professor-mark-hoffman

http://www.materials.unsw.edu.au/profile/mark-hoffman

Emeritus Professor John Carter is a geotechnical expert at the University of Newcastle

https://www.newcastle.edu.au/profile/john-carter

, and I suspect he was nominated to confirm whether there are any foundation / settlement issues which might have contributed to the damage; it may well be that the foundations are indeed perfectly sound, in which case, his role may be limited.

I wouldn't expect these two experts to tackle the investigation unaided - they will have ready access to the resources of their respective University Engineering faculties, and I would hope the Government will allow them to access other professionals and expert opinions as their investigations unfold.
I wouldn't expect a comprehensive report to be issued for several months.

http://julianh72.blogspot.com

 

[hokie66]

Agreed.

 

[rapt]

Jhardy1

Most of whom are away on holidays for the Summer break!

 

[jhardy1]

@rapt:
"Most of whom are away on holidays for the Summer break!"
Hence:
"I wouldn't expect a comprehensive report to be issued for several months."

http://julianh72.blogspot.com