Let's say, some nice paving stones, and some soil and plants. It doesn't need an engineer's calculations does it?

Let's say, some nice paving stones, and some soil and plants. It
doesn't need an engineer's calculations does it?

Might the roof have been designed and built by the same people who did
Southland Stadium?
--
Robin
reply to address is (meant to be) valid

On Sun, 24 Nov 2013 03:44:01 -0800, Matty F wrote:

Let's say, some nice paving stones, and some soil and plants. It doesn't
need an engineer's calculations does it?

Nah, little details like that are just bureaucracy and 'elf-an-safety
********.

On Sunday 24 November 2013 11:54 Robin wrote in uk.d-i-y:

Let's say, some nice paving stones, and some soil and plants. It
doesn't need an engineer's calculations does it?

Might the roof have been designed and built by the same people who did
Southland Stadium?

It will add up to quite a bit of weight - take the slabs, add a volume of
water equal to that occupied by the soil (waterlogged) and don't forget
snow. Should be easy to get a per-rafter loading figure worst case estimate.
Add 50% for good measure plus 100kg point load for when a fat bloke (not you
obviously) stands directly over one rafter centre span.

What have you under the roof? 100mmx50mm rafters - over what span and
centres?

I'm not saying it won't work - but I would do a sagulation type calculation!

--
Tim Watts Personal Blog: http://squiddy.blog.dionic.net/

http://www.sensorly.com/ Crowd mapping of 2G/3G/4G mobile signal coverage

On 24/11/2013 12:01 Tim Watts wrote:

On Sunday 24 November 2013 11:54 Robin wrote in uk.d-i-y:

Let's say, some nice paving stones, and some soil and plants. It
doesn't need an engineer's calculations does it?

Might the roof have been designed and built by the same people who did
Southland Stadium?

It will add up to quite a bit of weight - take the slabs, add a volume of
water equal to that occupied by the soil (waterlogged) and don't forget
snow. Should be easy to get a per-rafter loading figure worst case estimate.
Add 50% for good measure plus 100kg point load for when a fat bloke (not you
obviously) stands directly over one rafter centre span.

What have you under the roof?

A supermarket...

--
F

On Sun, 24 Nov 2013 12:01:28 +0000, Tim Watts wrote:

What have you under the roof?

54 Flat Latvians. (Flatvians?)

On Monday, November 25, 2013 1:01:28 AM UTC+13, Tim Watts wrote:

What have you under the roof? 100mmx50mm rafters - over what span and
centres?

Looks like steel trusses about 2 metres high, over a span of about 7 metres.
The trusses are bolted on at each end with 6 tiny bolts that seem to have vanished, and the trusses have broken in half. I can't see why they broke in half since there really wasn't that much weight over them.

Weight bearing calculations I'd imagine would be a given. One does not want
a planter complete with wet earth and plants on ones head wile watching the
TV after all.
Brian

--
From the Sofa of Brian Gaff Reply address is active
"Matty F" wrote in message
...
Let's say, some nice paving stones, and some soil and plants. It doesn't
need an engineer's calculations does it?

On Sun, 24 Nov 2013 12:30:55 -0800 (PST), Matty F wrote:

Looks like steel trusses about 2 metres high, over a span of about 7
metres. The trusses are bolted on at each end with 6 tiny bolts that
seem to have vanished, and the trusses have broken in half. I can't see
Why they broke in half since there really wasn't that much weight over
them.

The images I've seen show the trusses still attached at one end. So I
suspect the 6 bolts sheered, that end of the truss fell, when that it
hit the deck the momentum of the truss itself and the roof it was
supporting broke it.

Reports indicate that it didn't all go at the same time, the initial
collapse was multiple stage but fairly close together. Then another
happened once rescuers had arrived and were inside. B-(

--
Cheers
Dave.

Brian Gaff wrote:
Weight bearing calculations I'd imagine would be a given. One does not want
a planter complete with wet earth and plants on ones head wile watching the
TV after all.
Brian

I suspect a reference to the recent problem in Latvia when a newly
installed roof garden caused a supermarket roof to collapes, killing (at
the last count I heard) 57 people.

--
Tciao for Now!

John.

In article , John Williamson
wrote:
Brian Gaff wrote:
Weight bearing calculations I'd imagine would be a given. One does not
want a planter complete with wet earth and plants on ones head wile
watching the TV after all. Brian

I suspect a reference to the recent problem in Latvia when a newly
installed roof garden caused a supermarket roof to collapes, killing (at
the last count I heard) 57 people.

Estonia

--
From KT24

Using a RISC OS computer running v5.18

On Monday 25 November 2013 11:26 charles wrote in uk.d-i-y:

In article , John Williamson
wrote:
Brian Gaff wrote:
Weight bearing calculations I'd imagine would be a given. One does not
want a planter complete with wet earth and plants on ones head wile
watching the TV after all. Brian

I suspect a reference to the recent problem in Latvia when a newly
installed roof garden caused a supermarket roof to collapes, killing (at
the last count I heard) 57 people.

Estonia


No, Latvia. Zolitude suburb of Riga to be precise. In fact I stayed in the
middle of the 3 18 storey tower blocks pretty near to this supermarket when
I was travelling there in 1997. Maxima was not built then of course.

http://en.wikipedia.org/wiki/2013_Ri...store_collapse

--
Tim Watts Personal Blog: http://squiddy.blog.dionic.net/

http://www.sensorly.com/ Crowd mapping of 2G/3G/4G mobile signal coverage

On 24/11/2013 11:44, Matty F wrote:
Let's say, some nice paving stones, and some soil and plants. It doesn't need an engineer's calculations does it?

In the light of the recent supermarket collapes in Latvia I am surprised
you even need to ask this question!

http://www.bbc.co.uk/news/world-europe-25068291

You can get away with houseleeks and mosses that don't add too much
weight, but you erode your design overload margin for weight of snow.

--
Regards,
Martin Brown

Martin Brown wrote:
On 24/11/2013 11:44, Matty F wrote:
Let's say, some nice paving stones, and some soil and plants. It doesn't
need an engineer's calculations does it?

In the light of the recent supermarket collapes in Latvia I am surprised
you even need to ask this question!


Whoosh! ;-)

Tim

On 24/11/2013 11:44, Matty F wrote:
Let's say, some nice paving stones, and some soil and plants. It doesn't need an engineer's calculations does it?


It is possible that there had been calculations that showed that the
final design worked, but none that took into account how the materials
were going to be stacked during construction.

Colin Bignell

I'd read of the collapse and assumed it had been badly built. It never
occurred to me that somebody had taken a perfectly good design and
overloaded it. There was rather a smart design of cobblestones on the
part of the roof that collapsed last.

On Monday 25 November 2013 16:05 GB wrote in uk.d-i-y:

I'd read of the collapse and assumed it had been badly built. It never
occurred to me that somebody had taken a perfectly good design and
overloaded it. There was rather a smart design of cobblestones on the
part of the roof that collapsed last.

It was more than a "green roof" took - the Wikipedia article talks of
paving, benches - virtually a "park on the roof".
--
Tim Watts Personal Blog: http://squiddy.blog.dionic.net/

http://www.sensorly.com/ Crowd mapping of 2G/3G/4G mobile signal coverage

On 25/11/2013 16:43, Tim Watts wrote:
On Monday 25 November 2013 16:05 GB wrote in uk.d-i-y:

I'd read of the collapse and assumed it had been badly built. It never
occurred to me that somebody had taken a perfectly good design and
overloaded it. There was rather a smart design of cobblestones on the
part of the roof that collapsed last.

It was more than a "green roof" took - the Wikipedia article talks of
paving, benches - virtually a "park on the roof".


It could have been even worse. It might not have collapsed until there
were a couple of hundred people up there having a party.

On 25/11/2013 15:53, Nightjar wrote:
On 24/11/2013 11:44, Matty F wrote:
Let's say, some nice paving stones, and some soil and plants. It
doesn't need an engineer's calculations does it?


It is possible that there had been calculations that showed that the
final design worked, but none that took into account how the materials
were going to be stacked during construction.

The design would have needed to cover people, planters, 6 feet of snow
(this being Latvia), plus a safety margin.

On 25/11/2013 17:48, GB wrote:
On 25/11/2013 15:53, Nightjar wrote:
On 24/11/2013 11:44, Matty F wrote:
Let's say, some nice paving stones, and some soil and plants. It
doesn't need an engineer's calculations does it?


It is possible that there had been calculations that showed that the
final design worked, but none that took into account how the materials
were going to be stacked during construction.

The design would have needed to cover people, planters, 6 feet of snow
(this being Latvia), plus a safety margin.

Which is where we come to the difference in effect between distributed
loads (the finished garden and play area, with or without snow) and
point loads, such as a few pallets of paving stones stacked in the wrong
spot.

It certainly wouldn't be the first time that something had failed
because the loads imposed during construction significantly exceeded
those expected on the finished article. I know of at least one part
completed bridge that fell into a river because of that. Fortunately it
happened overnight, while the construction crew were off site.

Colin Bignell

On 25/11/2013 18:08, Nightjar wrote:
On 25/11/2013 17:48, GB wrote:
On 25/11/2013 15:53, Nightjar wrote:
On 24/11/2013 11:44, Matty F wrote:
Let's say, some nice paving stones, and some soil and plants. It
doesn't need an engineer's calculations does it?


It is possible that there had been calculations that showed that the
final design worked, but none that took into account how the materials
were going to be stacked during construction.

The design would have needed to cover people, planters, 6 feet of snow
(this being Latvia), plus a safety margin.

Which is where we come to the difference in effect between distributed
loads (the finished garden and play area, with or without snow) and
point loads, such as a few pallets of paving stones stacked in the wrong
spot.

It certainly wouldn't be the first time that something had failed
because the loads imposed during construction significantly exceeded
those expected on the finished article. I know of at least one part
completed bridge that fell into a river because of that. Fortunately it
happened overnight, while the construction crew were off site.


I can clearly see your point, but is a pallet load of cobbles going to
be that different a point load from a decent size planter? And even if
the designed-in planters are small, surely you need to allow for some
numpty coming along years later and replacing them?

On 25/11/2013 18:17, GB wrote:
On 25/11/2013 18:08, Nightjar wrote:
On 25/11/2013 17:48, GB wrote:
On 25/11/2013 15:53, Nightjar wrote:
On 24/11/2013 11:44, Matty F wrote:
Let's say, some nice paving stones, and some soil and plants. It
doesn't need an engineer's calculations does it?


It is possible that there had been calculations that showed that the
final design worked, but none that took into account how the materials
were going to be stacked during construction.

The design would have needed to cover people, planters, 6 feet of snow
(this being Latvia), plus a safety margin.

Which is where we come to the difference in effect between distributed
loads (the finished garden and play area, with or without snow) and
point loads, such as a few pallets of paving stones stacked in the wrong
spot.

It certainly wouldn't be the first time that something had failed
because the loads imposed during construction significantly exceeded
those expected on the finished article. I know of at least one part
completed bridge that fell into a river because of that. Fortunately it
happened overnight, while the construction crew were off site.


I can clearly see your point, but is a pallet load of cobbles going to
be that different a point load from a decent size planter? And even if
the designed-in planters are small, surely you need to allow for some
numpty coming along years later and replacing them?

If a single pallet or a change in planter made a difference, then there
obviously would not be a large enough safety margin.

I was thinking along the lines that it is quite common to stack all
deliveries in one spot, in order to leave the rest of the area clear for
work. That could easily result in a temporary situation with many more
tonnes of load in one spot than the roof truss under it was designed to
take.

Colin Bignell

On Tuesday, November 26, 2013 7:50:33 AM UTC+13, Nightjar wrote:

I was thinking along the lines that it is quite common to stack all
deliveries in one spot, in order to leave the rest of the area clear for
work. That could easily result in a temporary situation with many more
tonnes of load in one spot than the roof truss under it was designed to
take.

If you watch the video of the third collapse, a large area collapses at the same time for no apparent reason. There's nothing particularly heavy on top. The trusses seem to have broken in the middle. The trusses rest on columns that are still in place. The bolts are missing but merely hold the trusses in place.
During the collapse there are workers standing around who barely move.

On 25/11/2013 19:43, Matty F wrote:
On Tuesday, November 26, 2013 7:50:33 AM UTC+13, Nightjar wrote:

I was thinking along the lines that it is quite common to stack all
deliveries in one spot, in order to leave the rest of the area clear for
work. That could easily result in a temporary situation with many more
tonnes of load in one spot than the roof truss under it was designed to
take.

If you watch the video of the third collapse, a large area collapses at the same time for no apparent reason. There's nothing particularly heavy on top.
The trusses seem to have broken in the middle. The trusses rest on columns that are still in place.

It looks to me as though the trusses drop at the wall end first. My
guess would be that the columns might have been pulled out of true by
the earlier collapse and the trusses with them. Then, as everything
cools at night, the trusses contracted and simply slipped off their
supports at the wall end.

However, until somebody does an in depth investigation, it is all
supposition and you can't really draw conclusions from the collapse of
an already weakened structure.

The bolts are missing but merely hold the trusses in place.

That really is a rather important function. As already mentioned, it
suggests that they were sheared off by the loads imposed.

During the collapse there are workers standing around who barely move.

Not much reason to if you know that nothing is coming your way.

Colin Bignell