
Sydney Opal Tower: Thousands evacuated after 'crack' - rwmj
https://www.bbc.co.uk/news/world-australia-46671811
======
_fs
Fascinating post by a structural engineer who actually inspected projects by
this firm is over in the reddit discussion.
[https://www.reddit.com/r/sydney/comments/a91wit/opal_tower_s...](https://www.reddit.com/r/sydney/comments/a91wit/opal_tower_structural_damage_sydney_olympic_park/ecg3tpz/)

~~~
scarejunba
I wonder about the human effects of safety engineering. Say you require a 10x
margin because you know builders will dilute it to 5x undetectably (say it’s
under layers of other material or something). Every time you attempt to
compensate for the dilution of the standard in practice, they’ll undo it. But
if you stop, they may continue increasing the dilution. There’s a
normalization of deviance. And indeed most buildings will still stand because
the standard is attempting to handle six nines so everyone involved building
will probably ever build something that fails even if they diluted it to five
nines.

How do you encourage not doing that? Enforcement is one angle but are there
others? Force the buyers to have insurance and then let the insurance company
eat the risk assessment?

~~~
avar
This can also be handled by market forces. The people who expect to buy the
apartments in a high-rise like this could collectively hire their own
inspectors during construction, which would be answerable to them alone. The
obvious way to collectivize this is through insurance.

The problem stated by the linked Reddit commentator happens because the
interests of everyone (architects, engineers, constructors and inspectors)
currently align to de-prioritize safety.

There's numerous reasons why that doesn't happen. One being that no individual
apartments might have been sold before the construction is finished, but
another reason could be that building codes have been good enough, so people
think of that as a waste of money.

~~~
starshadowx2
Privately hired inspectors is a terrible idea. That leads it to only the rich
being able to afford to buy good inspectors leading to only the rich getting
safe housing.

Your whole comment can be condensed down to "I think poor people should have
to live in dangerously built housing and die but it'll be their own fault for
being poor."

There needs to be much more regulation with much higher penalties for
failures, and a dismantlement of the incentives of corruption.

~~~
avar
Consumers feel like they need to consider the safety rating of cars they buy,
and they pay to e.g. buy brands like Volvo or Tesla known for exceeding the
bare minimum when it comes to safety.

Yet I don't think you'd say that someone advocating that we continue that
system thinks that poor people should drive dangerously built cars, and it'll
be their own fault of they die in car accidents.

I'm pointing out that it's interesting that there seems to be no analogous
mechanism to ensure safety when it comes to buying houses, which are a much
bigger investment than a car.

> There needs to be much more regulation[...]

If the Reddit OP is to be believed the problem isn't that there aren't
regulations, but that they're systematically not being enforced.

> [...]with much higher penalties for failures[...]

I doubt that would work as well as aligning incentives. Even if you gave
engineers the death penalty for cutting corners they stand to make a lot of
money, and most of the time they'd get away with it. How many buildings in
Sydney _aren 't_ in the news?

> [...]a dismantlement of the incentives of corruption[...]

The best way to dismantle such incentives is to ensure that there's
conflicting interests. Here buyers are being screwed over by the builders,
certifying authorities and the councils because the interests of all three
align to screw buyers over.

~~~
ggcdn
> I doubt that would work as well as aligning incentives. Even if you gave
> engineers the death penalty for cutting corners they stand to make a lot of
> money, and most of the time they'd get away with it. How many buildings in
> Sydney aren't in the news?

In the US, Canada, and I presume Australia, the design engineer is actually
separate from the contractor. Generally, there is a developer who pays all the
design consultants and the contractor to make the project reality. So the
engineer really doesn't stand to make money from cutting corners. In fact,
they have much to lose, including their ability to continue practicing
engineering (it's a regulated profession) Their fee is the same if it gets
built correctly or not, and it costs them nothing extra to ensure it's built
correctly and mistakes are rectified.

------
danieltillett
I live in Sydney and I wouldn't buy any property built since 1970 and
especially any property built since 2000.

I have friends in the industry and the horror stories they tell me are
shocking. The real problem is coming in a few years as the waterproof
membranes protecting the rebar in all these high rise buildings has in almost
all cases not been put in correctly - in 10 to 20 years the concrete cancer
will be so bad that these building will need to be demolished.

~~~
cauldron
Fast economy then.

------
darkpuma
A one kilometer evacuation seems extreme. I assume dust is the justification
for that, but surely you could just tell people to close their windows if
they're not in range for falling debris.

And where are 3.14 square kilometers worth of people supposed to relocate
themselves to while waiting for the building to fall? Do hotels in Sydney
really have that sort of spare capacity? I wonder how many people are just
going to ignore that 1km evacuation order.

~~~
jpatokal
The building in question is in Sydney Olympic Park, a relatively sparsely
populated area far from the city center that used to be industrial wasteland
and is now mostly sports facilities (surprise!):

[https://maps.app.goo.gl/uZDA8](https://maps.app.goo.gl/uZDA8)

However, there have been quite a few shiny new apartments going up lately,
including this one. And as is the case for almost all residential construction
in Sydney lately, the quality tends to be shocking.

Update: the wide evacuation has been cancelled and most tower residents can
now return. However, 51 units have been declared structurally unsafe:

[https://www.smh.com.au/national/nsw/olympic-park-
residents-m...](https://www.smh.com.au/national/nsw/olympic-park-residents-
make-new-sleeping-arrangements-after-christmas-eve-
evacuation-20181224-p50o5h.html)

~~~
userbinator
_and most tower residents can now return. However, 51 units have been declared
structurally unsafe_

How does that work? That's a very strange statement to make. They're implying
those 51 units may collapse and leave the rest intact...? Even if I wasn't in
those 51, I wouldn't go back except perhaps to quickly get some stuff and move
out.

~~~
jfoster
That's a good point.

> NSW Police Acting Assistant Commissioner Julie Boon said "an internal
> support wall failed" in the building.

If one failed, though, is there any reason why others won't?

------
maccas
I am a civil engineer, preparing my thesis for a masters in geotechnical
engineering, and unemployed. Last job i had was with a precast crook employing
chinese designers and workers. I was forced to work as a draftsman, because I
could not get a job as engineer. I don't give two cents for the apartments
they are building, and I will comfortably move out of sydney once I get my
masters degree. That's the sole reason I am in Sydney. I may even contemplate
the possibility of moving overseas, Australia is becoming toxic for
professionals.

------
_kyran
To any structural engineers, what kind of tolerance are buildings like this
usually built to?

How much movement can they take? 2mm doesn't seem like much at all.

~~~
tomarr
2mm is fine and normally within measurement error.

However, buildings should be designed to not fail disproportionately, so there
isn't sudden failure such as like with the Miami footbridge. Design errors can
lead to sections being over reinforced or other issues which could lead to
collapse with little warning, which is what the concern will be.

Edit : also with cracks it depends on where they are and what causes with
them. Cracks are normal for concrete and the size should be controlled through
detailing. Where cracks are larger than this it can indicate whether there are
issues in bending/shear. Structural design also often takes into account
behavior of cracked concrete.

------
becga
Reading a lot of the comments here about poor quality of new construction have
resonated with my own recent experience: I left a luxury high-rise in Chicago
that had been built within the last ten years. The building was a later
addition to a retail building which contained restaurants and shops. Shortly
after moving in, I'd come home to find old grease and trash smells or the
smell which I can only describe as an old warehouse.

Thinking it was just residual odors, I would clean and re-clean and later
installed a couple of hepa portable filtration systems but the odors remained.
Started looking around only to find there was little to no sealant around
openings for the sprinkler systems, or underneath the sink unit/washing
machine, or any of the flooring etc.

Because the building was pressurized, the odors from the grease traps and/or
trash units deep below would come in through even the wall sockets. Mind you,
this wasn't every day but regular enough to be very unpleasant. Similar
complaints from other residents about cigarette odors coming in their
apartments but building management would never be able to trace down issue and
would just have restaurants empty out grease traps. All this for an apartment
I spent nearly 3,000 a month for. My advice to others is to be very skeptical
of any new buildings no matter the location and to be very sure you know what
you are getting into.

------
warent
I've never heard of anything like this. What happens now? Do they have to
demolish the entire building and start from scratch?

~~~
cronix
> I've never heard of anything like this.

This is kind of small compared to the Millennium Tower in San Francisco.
[https://www.cbsnews.com/news/millennium-tower-san-
francisco-...](https://www.cbsnews.com/news/millennium-tower-san-francisco-
leaning-tower-of-lawsuits-60-minutes/)

~~~
warent
I lived right near that thing and knew it was sinking a bit, but had no idea
it was leaning so far and with cracks too. WOW! That's terrifying, and I'm
more relieved than ever to be away from that thing.

Do you think anyone is going to do anything about this before a catastrophe?

~~~
cronix
I don't track it, but last I heard there was a proposal that would cost ~$100M
to drive micropilons down to bedrock, which is what should have been mandated
in the main design to begin with.
[https://www.sfchronicle.com/bayarea/article/Millennium-
Tower...](https://www.sfchronicle.com/bayarea/article/Millennium-Tower-
homeowners-propose-100-million-13440479.php)

Some windows are starting to crack as well.
[https://sf.curbed.com/2018/9/7/17829328/millennium-tower-
win...](https://sf.curbed.com/2018/9/7/17829328/millennium-tower-window-crack-
highrise)

~~~
HillaryBriss
I recall early stories about Millennium Tower and the builder basically
claiming, through a law firm, that it was a normal amount of settling and
everything was fine. Nothing to see here....

And I bet the same sort of response will come from the builder of Opal Tower
in Sydney.

~~~
TheGrassyKnoll
Millennium Tower will be a multi-decade lawyer-fest. At least four or five
parties will be suing each other: The designers, the builders, the city, the
apartment owners, insurance companies and probably the neighboring building
owners. What a mess.

------
bouncycastle
Annecdote: I often find that buildings in Australia vibrate / shake. One that
stands out in my mind, there's a shopping center in southern Sydney suburb of
Hurstville, at one particular spot, it feels like a short tremblor is striking
every 10 mins, to the point where I looked up if anyone else may be concerned.
There are a lot of cracks in the concrete, but I think that I've read
somewhere that as long as the cracks are vertical, that's not bad. However,
I'm somehow not convinced that this building would survive should a small real
earthquake occur (rare for Sydney, but there was a Newcastle one in recent
memory).

~~~
jboles
The Hurstville shopping centre is right above a train station; Australia is
largely earthquake free.

------
ams6110
Creaking and cracking noises are common in tall buildings from my experience,
but in this case it seems an actual crack in the structure has been found

~~~
paranoidrobot
But not suddenly starting and running for the course of an hour or so, and
audible from neighbouring apartment blocks.

------
matte_black
Will insurance cover this if the building is no longer safe for residents?

~~~
twelvechairs
Theoretically the system is set up to do this but in practice its complex and
takes time.

Insurers and lawyers can have a field day over liability. Was it the builders
fault? The structural engineer? The architect? Or caused after construction?
All of these will have their own insurance and all will avoid paying unless
its clear to a court that its their liability.

Of course major issues like this dont happen so often so theres little to
reference. But for example there was a recent case where the owners
corporration insurance refused to pay for a roof flying off after a storm
because in their view poor construction was to blame. Its a lot of time for
residents to be without a home while these things are sorted

[https://www.smh.com.au/national/nsw/insurer-rejects-
stormdam...](https://www.smh.com.au/national/nsw/insurer-rejects-stormdamaged-
lidcombe-apartment-building-claim-because-of-numerous-
defects-20160408-go1kz5.html)

~~~
jpatokal
In Sydney it's also common for builders/management companies/etc to declare
bankruptcy to deflect lawsuits etc, then set up a new company to continue
business.

~~~
hornetblack
They also don't have to finish everything in the building. Moved into a
building where the construction company did this, many things were unfinished.
Apparently didn't completely pay the workers, so they just took stuff when
they left.

