Sydney tower collapse fears

[member_xyz]

Not really relevant to electronics, but may be of interest to some viewers.

Must be terrible for residents and people affected literally on Christmas eve.

https://www.smh.com.au/national/nsw/opal-tower-residents-evacuated-after-concerns-building-may-collapse-20181224-p50o4b.html

[Halcyon]

This comes as no surprise. So many apartment buildings, semi-detached houses and even detached dwellings are slapped together without any regard to quality or longevity. Like with many things (Apple products excluded), you get what you pay for.

In 10-15 years, Sydney like most other modern cities will have residential premises literally falling apart.

Some people in Sydney are paying upwards of $1000 per square metre just for land, leaving very little in their budgets for the construction where it really should be the other way around.

Thin walls and windows, poor quality materials and fixtures and minimal insulation is what you find in the majority of "modern" homes these days. A lot of people tend to go for cosmetic appearance rather than quality and substance.

[Rerouter]

Yeah, Low quality materials are becoming more common in Sydney apartment complexes, even in the suburbs I've seen places where someone accidentally broke the gyprock and found no wall bracing, only some blocks of timber glued to the opposite sides gyprock to keep them both steady.

Housing in Sydney is one of those things where you never get what you pay for, you can only hope to make something off the rise in property value and jump ship to the next one before it sinks or breaks.

[SeanB]

Cowboy builders, and inspectors who do not do the work they are paid for by the taxpayers, either because of lack of knowledge, lack of resources or from taking some "cooldrink" money. Not exactly unknown all over the world, and here there is an advert on radio that implies that if you use this particular cement you can use less of it as "it goes so much further".

Some new buildings I would be concerned just leaning on a wall, let alone hanging a picture frame on them, because they have used so little cement in the mix, poor quality aggregate, less than the minimum required reinforcement, no brickforce, too much water in the initial mix, insufficient cure time before removing bracing, under thickness on the main floor structure and beams, and a whole slew of poor choices in construction. Plaster and paint unfortunately can cover a multitude of building sins, and one builder I know ( now in the UK), said even he would, as a cowboy builder, would think they were building on the far side of shady. Newly built walls, less that a year old, should not have the sun visible through them in the cracks, and you really should not have to wear hard hats indoors because of falling masonry.

[Synthtech]

Two years ago a building across the laneway opposite the rear of my business was demolished except for the front wall fascade (they do that for “historic” reasons to preserve to look of an old commercial structure) and then the workers proceeded to build a set of low-rise “luxury” apartments (maybe 6 on all) behind the fascade that were then sold at eyewatwring prices.  It all looked ultra-modern and hip and high tech and expensive.

I was amazed as I watched it all go up. It could be best described as being built out of compresssed tofu, sheet metal and Weet Bix with plenty of Gyprock thrown in and all held together by glue and staples. It looked like a 20 year building under the skin. There would have been very little sound isolation between the rooms, you would have had to run aircon 24/7 in the sydney summer and it was less than 6 months and the brown water stain lines were showing through the paint on the external masonry. I suspect that water leakage into the whole structure would also be a foregone conclusion. It was thrown up with very little care.

[grumpydoc]

France has had a spate of inner city buildings collapse apparently for no reason at all.

Except, perhaps that at least some of them were built without foundations 

https://www.theguardian.com/world/2018/nov/07/marseille-building-collapse-fifth-body-found-in-rubble

[cdev]

This sounds like a really dangerous situation.

 I am really glad that they heard the sounds and that the building officials responded appropriately!

[cdev]

If I am reading your description right you're likely talking about fake wood composite materials which are basically various kinds of fibers held together with copious amounts of glue.

That building may have some structural issues from what you're describing.

Composites have become quite popular because of low weight and high structural strength, however there a number of important issues which they tend to gloss over. The most important one is that if they get wet, especially if they get saturated with water they can 'delaminate' and sometimes they literally fall apart, they lose all their structural strength/shear strength!

The other is they emit lots of formaldehyde if they have ever gotten wet, indefinitely. One strong rainstorm while a building is being built, before the material is covered in some manner (that has to be done) is enough to do all this.

In fact, even if they have never gotten wet during the construction phase (when it usually happens) and still have all their structural strength, they still emit what some consider to be dangerous amounts of formaldehyde. Its enough to be irritating to most people, thats for sure.

Another problem is - they have a serious problems with mold growth, much more than real wood has. But the structural strength issue is particularly dangerous.

This "delamination" is particularly bad after extreme weather events. After Hurricane Sandy it was fairly common to see the same kinds of damage again and again. many houses lower floor collapsed in a diagnonal manner because of total loss of shear strength of the lower story due to flood waters and some small push sidewards caused sudden delamination

Formaldehyde can make people feel ill all the time and not know why.

So buildings built with large amounts of these materials (basically almost all new construction in some countries!) should be mechanically ventilated year round. Doing that economically in a cold winter climate basically requires a heat recovery ventilator.

They are mandatory on new construction in some countries but not in others.

I was amazed as I watched it all go up. It could be best described as being built out of compresssed tofu, sheet metal and Weet Bix with plenty of Gyprock thrown in and all held together by glue and staples. It looked like a 20 year building under the skin. There would have been very little sound isolation between the rooms, you would have had to run aircon 24/7 in the sydney summer and it was less than 6 months and the brown water stain lines were showing through the paint on the external masonry. I suspect that water leakage into the whole structure would also be a foregone conclusion. It was thrown up with very little care.

[nctnico]

Thin walls and windows, poor quality materials and fixtures and minimal insulation is what you find in the majority of "modern" homes these days. A lot of people tend to go for cosmetic appearance rather than quality and substance.

You are right about that. This house (near where I live) is so fuggly that the real estate agent didn't even want to post a close-up picture:

Yes. It is a metal box. The interior is even worse:


It has been for sale for over half a year and it will probably be for sale for a long time. The new owner will likely tear it down and build a proper house.

[vtwin@cox.net]

Yeah, Low quality materials are becoming more common in Sydney apartment complexes, even in the suburbs I've seen places where someone accidentally broke the gyprock and found no wall bracing, only some blocks of timber glued to the opposite sides gyprock to keep them both steady.

To be fair could this be a matter of an improper foundation which caused a portion of the building to settle/crack, rather than improper building materials themselves?

[Halcyon]

Yeah, Low quality materials are becoming more common in Sydney apartment complexes, even in the suburbs I've seen places where someone accidentally broke the gyprock and found no wall bracing, only some blocks of timber glued to the opposite sides gyprock to keep them both steady.

To be fair could this be a matter of an improper foundation which caused a portion of the building to settle/crack, rather than improper building materials themselves?

Of course it could, but I'm just saying it as I see it.

There are thousands and thousands of homes popping up in these so-called "modern" suburbs which are just awful quality for example internal doors are literally made of cardboard (they are called hollow or honeycomb core). External walls are thin and built so close to next door that you can hear your neighbours going to the bathroom. I'm honestly not exaggerating here.

As you drive past it, all you see is a sea of grey rooftops all squeezed into tiny little blocks. A few examples of these "cookie cutter" suburbs is Oran Park and Spring Farm in south-western Sydney and Jordan Springs in western Sydney - it is truly a depressing sight.

Here is a link to some aerial photos of both suburbs: https://www.perthnow.com.au/news/nsw/the-westward-expansion-ng-47c65b32e8fdc5b707f721b375681974

[SeanB]

Same here, just they are sold as high value units in new developments, and the value of the unit compared to the build price and quality is incredibly high. 100m2 house with 3 bedrooms, build cost is around the same per square, excluding finishings, as that used to build low cost houses, yet they are sold for millions while the RDP houses, those that do not fall apart within a year or two, are given out for free. Density of the developments is the same as well more or less.

[Brumby]

There are thousands and thousands of homes popping up in these so-called "modern" suburbs which are just awful quality for example internal doors are literally made of cardboard (they are called hollow or honeycomb core). External walls are thin and built so close to next door that you can hear your neighbours going to the bathroom. I'm honestly not exaggerating here.

No ... No exaggeration at all.  I've often mused when they build these houses if you had two bathrooms either side of the fence, you could pass the shampoo from neighbour A to neighbour B while each was in their shower.  When you look closely, that's not too far out of the realm of possibility.  Cats don't need to jump from roof to roof, they can just step over ... maybe stretching a bit.

As you drive past it, all you see is a sea of grey rooftops all squeezed into tiny little blocks. A few examples of these "cookie cutter" suburbs is Oran Park and Spring Farm in south-western Sydney and Jordan Springs in western Sydney - it is truly a depressing sight.

Here is a link to some aerial photos of both suburbs: https://www.perthnow.com.au/news/nsw/the-westward-expansion-ng-47c65b32e8fdc5b707f721b375681974

Tree count, anyone .... ?

[cdev]

In Oakland, CA (and many other cities around the US) there are a great many single story houses built on small narrow lots fairly close to the house next door (maybe at the most four or five meters between them. Many of these houses are built in the so called "Craftsman bungalow" style from kits that cost around $1000 at the time and they are really quite nice.

It is possible to make nice small houses on lots of that size. These houses are a good example.

They have aged quite well. many of them are worth a lot of money now.

[SparkyFX]

Another video on the topic of poor quality buildings:

Are NEW Chinese buildings really FALLING DOWN?


Isn´t there any liability by the construction company? I mean there are plenty of cases in which the turnkey homebuilding went wrong over here and adjacent lawsuits take forever, but the average (private, planning for minimum 20 years) home builder over here would not accept such solutions.

[nick_d]

My story is that I was working in the Netherlands for my company doing EE and software work and formed some relationship with colleagues, including this one family that was especially kind to me and that I've kept in touch with.

When I first met them I used to go to dinner often in their inner-city (Diemen) apartment, a large 2-storey apartment in an older building that seemed to use a lot of concrete (at least based on what I saw in the public areas, stairwell etc). It was quiet and peaceful and well built, but also rented.

So with much anticipation they moved to a brand new 3-storey attached house in the Polder about 30 mins from Amsterdam, the Polder means reclaimed land and basically if you have ever seen a "new suburb" you will know what the Polder is like. Beautiful to the eye, cheaply constructed!

Basically it starts as a gigantic Government sponsored engineering project to drain it and either build dykes or truck in millions of tons of earth from elsewhere or both. Then it is parcelled up and contracted out to development companies that build roads, artificial lakes, rows of apartments etc.

So I was very admiring of this beautiful new suburbs, the sparkling clean canals, parks and bike paths etc. I happen to remember they lived in "Islands Town" or similar and the streets were named like "Azores Street", "Maldives Street" and so on. To get there from the freeway you pass through a number of similarly but differently themed suburbs, etc.

I was looking into investing there. Searched through lots of real estate listings etc, although there was not a lot for sale since they are sold off the plan before they're built. Those who did sell were the lucky ones -- I went back there recently and it was an utter hell-hole. It really shattered my illusions.

Part of the problem is basically that all the houses are built at the same time and hence they all get that tatty run-down look at the same time (about 10 years later). Some, like my friends, had maintained and repaired, kept the strip of garden by the front door neatly trimmed etc, most hadn't bothered.

I think what happens is when the gloss wears off, those who can move elsewhere, leaving a vacuum where basically drifters and transients move in. I'm sure it kills the investment.

Give it 30-40 years and individual renewal projects will eventually improve matters, but I sure hope they use good building materials. Cement sheet often tends to lift and warp a bit over the years, ruining the neatly rendered look and revealing the structure for the house of cards that it is!

cheers, Nick

[MT]

I hope it will collapse and revile a biiiiig finical scandal causing unrest and turmoil and by so focusing light on the housing bubble thats going on down under! Well, not only down under even here on top we have a housing bubble, well all over the planet as we getting closer towards the planetary financial meltdown!

This one is quite creepy the dude pooking away column cement is about 10 stories up in a 20+ stories building somewhere in china i recall, but not 100% sure.


NIST and China gov column stress tests.

[Gregg]

In Oakland, CA (and many other cities around the US) there are a great many single story houses built on small narrow lots fairly close to the house next door (maybe at the most four or five meters between them. Many of these houses are built in the so called "Craftsman bungalow" style from kits that cost around $1000 at the time and they are really quite nice.

It is possible to make nice small houses on lots of that size. These houses are a good example.

They have aged quite well. many of them are worth a lot of money now.

Most of Foster City is built on land that used to be the San Francisco landfill; and before that it was bay tide lands which these days would be strictly forbidden to develop.  Plus the whole area is adjacent to the San Andreas fault.  It basically boils down to politics and who spends the money to grease the political machine.  Sidney is not alone in the area of poor building and greedy politics.

[cdev]

Yes, I totally see what you are saying.

As somebody who reads planning documents, it seems to me that when builders build neighborhoods of townhouses only meant to last 20 years that is entirely the planners intention for those areas also, basically to fill them up with something shoddy and temporary until the next phase comes along, at least it seems they think that way from the language they use.

......

[edy]

I read some reports and they mentioned 1-2mm of movement of the building. How would they be able to determine this to such accuracy? Is this just an estimate based on the size of the crack? And if an internal support wall cracked, how can they be sure it won't sheer off at some point... This doesn't instil confidence. Another issue is that the property value now of this building is forever scarred.... NOBODY in their right mind will move in now unless there is a significant financial incentive (i.e. big drop in real estate value) to buy an apartment in this building. I am certain there will also be a number of people selling to get out. This is going to be a disaster either way, whether the building stands or not. I hope for the sake of innocent human lives that it stands... But as far as the economic repercussions, that is going to be years to sort out.

I mean, look at the price of this place:

https://www.realestateview.com.au/real-estate/1801-opal-tower-australia-avenue-sydney-olympic-park-nsw/property-details-buy-residential-11452676/

$720,000 for a 1 bed 1 bath 1 car apartment? I thought Toronto prices were insane... this beats the cake! Who wants to bet that the prices in this building will deflate very quickly after this incident?

Here's another apartment, 2 bed 2 bath 1 car and the listing if you scroll down the bottom has a bunch of recent sales and prices for various apartments in the building... all in the $700-800k range:

https://www.realestate.com.au/sold/property-apartment-nsw-sydney+olympic+park-127955206

Here's one for $935,000:

https://www.realestate.com.au/property-apartment-nsw-sydney+olympic+park-128043754

No amount of reassurance by engineers will tame the market collapse for this building. I'm not sure if they can sue or get some kind of insurance fund available to compensate for the drop in the value of their homes, or everyone is just S.O.L.

[cdev]

Money is the root of all evil.

[cdev]

I read some reports and they mentioned 1-2mm of movement of the building. How would they be able to determine this to such accuracy? Is this just an estimate based on the size of the crack?

Laser ranging and RTK-GPS - see https://rtklib.com and the home page of its author Tomoji Takasu, which you can find at the very bottom of that page.

Check it out, its very interesting and you can do it too. For not that much money!

[edy]

Yes, thanks, laser-ranging and interferometry would do it. I guess my question is not that they can measure a change of 2mm, but what is the normal "error" expected when measuring a building or any such structure? For example, there must be various effects just from natural causes that can cause minor movement, swaying, error in accuracy, etc? Are they using another building as their original reference point? Some kind of surveying reference points? GPS? It just seems that 2mm is so small a distance that the error expected in measuring and surveying buildings such as this would be expected, even under normal situations.

One other thing that I can't reconcile with this "2mm shift" statement is the following quote from this article:

https://www.theguardian.com/australia-news/2018/dec/25/sydney-olympic-park-opal-tower-evacuation-51-units-deemed-unsafe

On Tuesday morning, the Fire and Rescue NSW superintendent, Adam Dewberry, said people first noticed the issue because the door jambs of the building shifted and residents couldn’t open their doors.

So can 2mm change cause door jambs of buildings to shift enough to affect doors opening? My gut is telling me that the tolerance of a typical door jamb and the ability to swing open a door is more than 2mm. Last time I installed and adjusted a door, I did not get out my calipers and get it within 2mm accuracy.... my door worked fine. So unless these doors are super-tight-tolerances, I can't understand what this 2mm shift is... unless the building moved 2mm horizontally/laterally (when measured externally) but the crack has caused the shear to move much greater in a vertical direction. Either way that is not a good situation.

[cdev]

Around four years ago a high-rise building collapsed in Pyongyang. Luckily there were a few minutes warning and many of the people got out, but not all.

For some reason people had occupied the building before it was officially finished.

[edy]

Around two or three years ago a building of around that size built in a similar style collapsed in Pyongyang. Luckily there were a few minutes warning and most of the people got out, but not all. For some reason people had occupied the building before it was officially finished.

I saw some footage on the Pyongyang building and I can't imagine the level of engineering or safety in North Korea would be anywhere close to the same levels in Australia. Have a look at this footage of them building this place: