BS: How high can a brick building go?

Subject: BS: How high can a brick building go?
From: GUEST,Dazbo
Date: 09 Nov 06 - 06:57 AM

Been puzzling me for a while now but if you built a building out of normal bricks and mortar (where the bricks and mortar take the full weight of the building) how high could you build it before the bricks at the bottom can no longer take the weight? Which would give way first the bricks or the mortar?

Subject: RE: BS: How high can a brick building go?
From: catspaw49
Date: 09 Nov 06 - 08:02 AM

You really need to get out more. Go to the park and fly a kite. Sing a few tunes with friends. Good luck.

Spaw

Subject: RE: BS: How high can a brick building go?
From: Bunnahabhain
Date: 09 Nov 06 - 08:22 AM

Depends how you designed it. If you just built a pyramid, with very few internal spaces of any kind, then the highest you could go on Earth would be somewhere above 8 km above sea level, assuming you have the correct geology under you.

Mountains on earth tend to get no higher than 8 km, as higher than that makes them too heavy, and so they cause the whole crust of the earth in that area to sink. If you build just one isolated brick mountain, on a geologically stable area, you could probabaly get a lot higher, as the load causisng the crust to sink would be far smaller than with a whole chain of mountains.

Bricks Vs Motar. Depends on quality. If you use a good, high cement motar, with very cheap, soft bricks, or cheap, sandy motar with engineering bricks, you'll get obviously different results.

If I'm feeling up to it, and John in kansas doesn't do it first, I'll calculate how many bricks you could stack on top of each other before the bottom one crumbles. Not until after coffee though.

Subject: RE: BS: How high can a brick building go?
From: Deckman
Date: 09 Nov 06 - 08:27 AM

Actually, the answer is VERY simple: you can build a brick building ALL THE WAY FROM THE GROUND, TO THE VERY TOP! (these darn engineers ... always wanting to make things way too complicated). CHEERS, Bob

Subject: RE: BS: How high can a brick building go?
From: Becca72
Date: 09 Nov 06 - 08:36 AM

Nice, Deckman, very nice LOL

Subject: RE: BS: How high can a brick building go?
From: Rapparee
Date: 09 Nov 06 - 08:55 AM

Well, probably higher than your head. You'd almost certainly need a ladder.

Subject: RE: BS: How high can a brick building go?
From: MMario
Date: 09 Nov 06 - 08:59 AM

It really depends on how much explosive you use.

Subject: RE: BS: How high can a brick building go?
From: Dave Hanson
Date: 09 Nov 06 - 09:04 AM

There are no ladders long enough.

eric

Subject: RE: BS: How high can a brick building go?
From: Bill D
Date: 09 Nov 06 - 10:08 AM

There are bricks, and then there are BRICKS....some are cheap, some are well made. Makes a big difference.

"The compressive strength of bricks produced in the USA ranges from about 1000 lbf/in² to 15,000 lbf/in² (7 to 105 megapascals), varying according to the use to which the bricks are to be put."

see here

(The Chrysler building in New York is 1000+ feet, but one can debate HOW the brick is used & laid....)

Subject: RE: BS: How high can a brick building go?
From: Mooh
Date: 09 Nov 06 - 10:37 AM

How much jet fuel do you have?

I like the kind of bricks they take out of the ground in the Bruce, huge squared blocks of "angelstone". I'd rather they didn't quarry them, but they sure would make a fortress of a home. Driving by the quarry I often have daydreamed of another stonehenge, pyramid, or amphitheatre. Generally I dislike tall buildings.

Peace, Mooh.

Subject: RE: BS: How high can a brick building go?
From: Paul Burke
Date: 09 Nov 06 - 10:38 AM

The real limit won't be the compression limit of the brick, but that any openings for doors and windows will tend to create sideways forces that could eventually put part of the structure into tension. When that happens, bricks and mortar are bad news.

There are some brick churches of cathedral size in central Europe.

Subject: RE: BS: How high can a brick building go?
From: Bunnahabhain
Date: 09 Nov 06 - 11:06 AM

Using the range of values for the compressive strength and density of high quality brick masonry, the answers come out in a range between 4653 and 5273 meters. This is for a solid tower the same width up its entire height.

This seems about right. The instinct for 'is this answer in the right order of magnitude?' is very useful. There's a different between a wrong answer, and a plain silly one.

The Chrysler building is brick on a steel frame, Bill.

Subject: RE: BS: How high can a brick building go?
From: bobad
Date: 09 Nov 06 - 11:08 AM

What would it be using Lego bricks?

Subject: RE: BS: How high can a brick building go?
From: Bunnahabhain
Date: 09 Nov 06 - 12:14 PM

Lego Bricks are ABS plastic.

ABS has a compressive strength of 65 MPa, density about 1020 Kgm^-3

Therefore, a uniform solid ABS tower comes out as 6495 meters.

Assuming lego bricks are equally strong in all directions, this should means one third of the materiel does not add to vertical strength (I think), so giving a lego height of 4326 M.

Subject: RE: BS: How high can a brick building go?
From: catspaw49
Date: 09 Nov 06 - 12:24 PM

Uh, Bunny.......You need to get a kite and join Daz in the park. Relax.   Take a break. Eat some cashews.

Spaw

Subject: RE: BS: How high can a brick building go?
From: Bunnahabhain
Date: 09 Nov 06 - 12:29 PM

I'm stuck at the computer doing almost useful things, it's dark and wet out there and the kite doesn't work as well indoors, the infomation is easily and quickly to hand, and the calculations are trivial.

Subject: RE: BS: How high can a brick building go?
From: catspaw49
Date: 09 Nov 06 - 12:30 PM

Okay then.....I forgive you. But try to pick one up for the weekend. The weather might improve(;<))

Spaw

Subject: RE: BS: How high can a brick building go?
From: Peace
Date: 09 Nov 06 - 12:58 PM

"How high can a brick building go?"

Depends how much Semtex you use.

Subject: RE: BS: How high can a brick building go?
From: NH Dave
Date: 09 Nov 06 - 01:09 PM

Don't forget that for buildings much over two stories high, you need to tie the opposite outside walls together with something, if outside buttresses are not going to be used. Many older buildings in the US have 1/2" rods extending from side to side of the buildings, threaded on the extreme ends, with a nut and large pressure plate, to tie the two sides of the building together. These ties are placed every 6 - 12 inches along the outside of the wide side of the building, and keep the weight of the bricks above from bowing the wall, and then collapsing the wall (outwaards)completely.

Dave

Subject: RE: BS: How high can a brick building go?
From: McGrath of Harlow
Date: 09 Nov 06 - 01:17 PM

There are some brick churches of cathedral size in central Europe.

I suspect that they'd probably be brick cladding on a structure made of stone or some kind of composite.

Subject: RE: BS: How high can a brick building go?
From: Peace
Date: 09 Nov 06 - 01:28 PM

"Many older buildings in the US have 1/2" rods extending from side to side of the buildings"

It's important during fire situations, too. Metals expand with heat, and walls beginning to bulge near the pressure plates are an indicator that there has been lots of heat inside the structure and the possibility of floor collapse inside. If that occurs, there may be wall collapse also.

Subject: RE: BS: How high can a brick building go?
From: Rapparee
Date: 09 Nov 06 - 02:20 PM

Peace, if there's a fire I'm gonna let the pros deal with it. Well, a little one I'd try to put out, but anything of any size, nope!

My uncle was inside a burn when the floors collapsed. Fortunately he survived to tell the tale and father some of my cousins. Even better, nobody was even hurt on that fire!

Subject: RE: BS: How high can a brick building go?
From: Little Hawk
Date: 09 Nov 06 - 03:02 PM

It can go as high as the top of the top floor.

Subject: RE: BS: How high can a brick building go?
From: Richard Bridge
Date: 09 Nov 06 - 05:11 PM

McGuinn and McGuire couldn't get much higher, in LA you know hwere it's at.

Subject: RE: BS: How high can a brick building go?
From: JohnInKansas
Date: 09 Nov 06 - 05:36 PM

The need to tie the sides together is just part of the real limit on how high a brick (only) structure can go. Even though bricks are relatively "stiff," they still can be compressed by the weight of the layers above.

If they can be compressed, a brick column can bend due to very slight differences in compression on one side vs the opposite side.

If the restoring moment produced by the bending reaches the point where the restoring moment provided by the tensile properties of the structure increases less rapidly than the additional bending moment due gravity acting on the curvature of the structure, one has exceeded the column buckling length-to-cross-sectional-moment ratio, and the structure will fail.

Since brick structures have very low tensile strength, which is the property required for the "long side of the curvature," the actual limit for a straight-up brick structure is quite a bit lower than what's required to "crush the bricks."

It's necessary only to observe that nobody (usually) builds brick structures like smokestacks and such much beyond 80 to 120 feet tall to guess, with pretty good assurance, that anything much beyond that probably doesn't meet acceptable margins of safety using brick and mortar construction alone. Even at those heights, additional reinforcement usually is needed to safely hold things all together when the wind blows.

The widespread use of vaulting, buttresses (flying and otherwise) in large structures made of stone is a necessary thing. Quite a few of the old cathedrals took many years to build, and occasionally collapsed during their construction and had to be redesigned to add compensations for the limited properties of the materials used.

John

Subject: RE: BS: How high can a brick building go?
From: Bert
Date: 09 Nov 06 - 08:06 PM

It depends on how many bricks you've got.

Subject: RE: BS: How high can a brick building go?
From: Donuel
Date: 09 Nov 06 - 08:23 PM

If the base/foundation were the size of Texas, it could go purty durn high.

Subject: RE: BS: How high can a brick building go?
From: Bee-dubya-ell
Date: 09 Nov 06 - 08:29 PM

Right, Bert. And it depends on whether you stack 'em this way "_ _ _ _ _" or this way "| | | | |"

Subject: RE: BS: How high can a brick building go?
From: Deckman
Date: 09 Nov 06 - 08:29 PM

GEEZE LOUSE! Why don't you guys go read read a book ... or somthin'!

This thread kinda reminds me of a comment that a friend made to me 40 years ago: "Those damned civil engineers. They'll NEVER be happy until
they can place a marble on the ground in Chicago and it'll roll to California!" CHEERS, Bob

Subject: RE: BS: How high can a brick building go?
From: Rapparee
Date: 09 Nov 06 - 09:10 PM

You can get a pretty big pile of 'em as long as Officer Pupp don't ketch you.

Subject: RE: BS: How high can a brick building go?
From: *Laura*
Date: 09 Nov 06 - 09:24 PM

Bert beat me to it......

Subject: RE: BS: How high can a brick building go?
From: Rowan
Date: 10 Nov 06 - 12:42 AM

JohninKansas usually has lucid and comprehensive explanations so I'm surprised he left out the (possible) effects of expansion of the mortar during the curing process. It's a very long time since I had the formulae and figures for such calculations but I seem to recall that this also imposed a limit on the overall length of a brick wall (of any height) without expansion joints in it. When I was at La Trobe Uni (Melbourne) the gossip was that the Admin building (I forget whose name it carried) had the longest brick wall with no expansion joints. Like many such boasts it was qualified with "in the sountern hemisphere" but it was a very long wall.

Cheers, Rowan

Subject: RE: BS: How high can a brick building go?
From: Peace
Date: 10 Nov 06 - 01:49 AM

The answer? LEGOS.

Subject: RE: BS: How high can a brick building go?
From: Liz the Squeak
Date: 10 Nov 06 - 04:57 AM

Bunnybrain (can't be arsed to scroll up and find correct spelling) - re: Lego bricks - depends entirely on what state your feet are in when you stand on them.

When feet are encased in army boots, the bricks are pretty fragile but when barefooted, they take on an indestructable quality matched only by drunkards and Ethel Merman.

LTS

Subject: RE: BS: How high can a brick building go?
From: gnu
Date: 10 Nov 06 - 07:30 AM

GUEST,Dazbo 09 Nov 06 - 06:57 AM "Been puzzling me for a while now but if you built a building out of normal bricks and mortar (where the bricks and mortar take the full weight of the building) how high could you build it before the bricks at the bottom can no longer take the weight? Which would give way first the bricks or the mortar?"

IF the first question is, "How high can a brick wall be built before the bottom bricks can no longer take the weight?" (That is, considering only the weight of the wall itself - ignoring ALL other loads.), about 1200 feet for cheap (1000psi compressive strength) bricks.

Regarding the second question, the bricks.

Now, you can take into account many load and quality factors, some as discussed above, each reducing practical wall height accordingly. For instance, consider Liz's "drunkards" above. Clearly, if this wall was laid by the most famous mason of all, Tim Finnegan, and he had no fall protection as required by the safety authority having jurisdiction, the maximum wall height would be about eight feet.

Subject: RE: BS: How high can a brick building go?
From: Bunnahabhain
Date: 10 Nov 06 - 08:33 AM

Of course, if you took those same bricks, and buid the same towers on Mars, where Gravity is about 38% of Earths, then a Brick tower could reach about 14 Km tall, assuming you had motar that would cure properly in the cold, expansion jointing, ans proper butresssing.

If you wanted to be silly, you then build this lot on top of the Martian Volcanoes, and you'd have an instant space port, as it would be above virtually all of the Martian atmosphere....

Subject: RE: BS: How high can a brick building go?
From: Rapparee
Date: 10 Nov 06 - 09:01 AM

Bunn, are you then advocating the use of brick spaceships? I've heard of, and even seen, brick shithouses and I would assume that some of those might possibly have achieved orbit if the users thereof provided the right fuel. But brick spaceships would open a whole new era in space travel.

Subject: RE: BS: How high can a brick building go?
From: Rapparee
Date: 10 Nov 06 - 09:09 AM

Which reminds me of the sign the NPS had posted on the lighthouse at the Outer Banks before it was moved inland. It read, in part, "The lighthouse will be moved vertically." I asked a Ranger if they were going to use surplus rockets or missiles, but he ignored me.

Subject: RE: BS: How high can a brick building go?
From: GUEST,Mr Red (with a minor fascination for Blue Br
Date: 10 Nov 06 - 10:24 AM

You don't hire buildings - you rent them (with that Semtext mentioned)

However if you higher them - that's another storey

Subject: RE: BS: How high can a brick building go?
From: GUEST,Bruce Baillie
Date: 10 Nov 06 - 12:10 PM

I seem to recall seeing a TV programme which stated that the Flatiron Building in New York was the tallest building built purely from brick with no steel frame, and has walls at the bottom nine feet thick.

Subject: RE: BS: How high can a brick building go?
From: Bee-dubya-ell
Date: 10 Nov 06 - 12:25 PM

Sorry, Bruce, but according to the Wikipedia article on the Flatiron Building (click):

Since it was one of the first buildings to use a steel skeleton, the building could be constructed to 285 feet, which would have been very difficult with other construction methods of that time.

Subject: RE: BS: How high can a brick building go?
From: Rapparee
Date: 10 Nov 06 - 07:34 PM

The Cape Hatteras lighthouse, that was the one.

Subject: RE: BS: How high can a brick building go?
From: NH Dave
Date: 10 Nov 06 - 09:31 PM

I suspect that the vertical move was mostly to allow the movers to get beams and dollies under the lighthouse so they could then move it horizontally.

Dave

Subject: RE: BS: How high can a brick building go?
From: Peace
Date: 10 Nov 06 - 09:36 PM

Moving the CH lighthouse. Diary.

Subject: RE: BS: How high can a brick building go?
From: frogprince
Date: 10 Nov 06 - 09:41 PM

You can theorize all you want with your godless secular speculation, but I'll guarantee you this; if you try to build it up to the heavens, God's gonna knock it down, and mix up all your languages so you can't try that again!

Subject: RE: BS: How high can a brick building go?
From: Rapparee
Date: 10 Nov 06 - 09:51 PM

Yeah, FP, that's what happened the last time I did something like that. And just getting lunch afterwards was a pain -- trying to order a hot dog took me over an hour.

Subject: RE: BS: How high can a brick building go?
From: Peace
Date: 10 Nov 06 - 09:52 PM

YEAH. You were in the lineup for the washroom. Sheesh!

Subject: RE: BS: How high can a brick building go?
From: The Fooles Troupe
Date: 10 Nov 06 - 10:04 PM

Fascinating what musos trying to avoid practice will come up with - you lot should see my 9 year old goddaughter during 'guitar practice' time... :-)

Subject: RE: BS: How high can a brick building go?
From: Rapparee
Date: 10 Nov 06 - 10:08 PM

I remember just trying to figger out which was the gents -- doors labeled "Femmes" "Fir" "Mna" "Hombres" "婦女" "люди" "homens" "άτομα" "Frauen" and more! Finally I just stood in the same line as Peace and hoped he knew what he was doing.

Subject: RE: BS: How high can a brick building go?
From: The Fooles Troupe
Date: 11 Nov 06 - 03:39 AM

"if you try to build it up to the heavens, God's gonna knock it down"

So just how high would the Tower of BaBel have been - I suspect from the ancient time that it was probably built from mud brick, perhaps reinforced with straw... :-)

Subject: RE: BS: How high can a brick building go?
From: Liz the Squeak
Date: 11 Nov 06 - 03:43 AM

Some of that mud and straw would have been dung and animal hair... gives better cohesion and what's more, it sticks together better too!

LTS

Subject: RE: BS: How high can a brick building go?
From: The Fooles Troupe
Date: 11 Nov 06 - 03:48 AM

... one wonders, how do you know? :-)

not sure if the engineers here have tables for dung coefficents....
:-)

Subject: RE: BS: How high can a brick building go?
From: Mr Red
Date: 11 Nov 06 - 04:59 AM

Well at least it is made of Bullshit so we have the thread in the right place.

Isn't the dung brick technically called cob? Still plenty of old houses in Devon built that way. Ususally no more that two storeys but the Pennymoor Song and Ale (June - Cruwys Arms - Pennymoor) used to be held on the Penny premises in a barn built of cob and that was high enough to hold three storeys but had no floors above ground level.

Subject: RE: BS: How high can a brick building go?
From: gnu
Date: 11 Nov 06 - 06:06 AM

Ancient time?

Subject: RE: BS: How high can a brick building go?
From: Rapparee
Date: 11 Nov 06 - 08:12 AM

Don't use water in your mixture, use bullock's blood.

Subject: RE: BS: How high can a brick building go?
From: Liz the Squeak
Date: 11 Nov 06 - 12:58 PM

The blood usually goes in the lime for the final wash - gives the house a lovely reddish brown colour that over the years fades to pink.

I know about dung in bricks because it's still used in some countries. Why waste valuable topsoil on bricks when you can use what the animals give free and gratis.... We have a Victorian house and whilst replastering a wall I noticed that the plaster contained rather a lot of coarse hair - probably horse, to aid cohesion.

AS for the stickiness of dung... I grew up on a dairy farm. There is NOTHING stickier than the dung of a cow that's been fed on fresh grass. Unless it's the smell.. that sticks around for months!

LTS

Subject: RE: BS: How high can a brick building go?
From: Gervase
Date: 11 Nov 06 - 01:25 PM

Of course, if you build with a lime mortar rather than OPC you don't need expansion joints.
In truth, most modern mortar is ludicrously over-engineed for what it needs to do. A standard 5:1 mix has a compressive strength of around 70Nm/mm, whereas your average housebrick has a compressive strength of around 11Nm/mm. That means that, under stress, the bricks crack first, which is not a good idea (and which is why modern houses are built on massive concrete foundations and why, when you use OPC mortars and renders for repairing old houses, you end up with cracks and damp problems). Ideally the mortar should be softer than the stuff it's binding.
And don't get me started on the wonders of cow-dung - I've got a job coming up next week which will require plenty of the fresh stuff. The client has been warned about the whiff, but says she doesn't mind!

Subject: RE: BS: How high can a brick building go?
From: EBarnacle
Date: 11 Nov 06 - 01:26 PM

We really need to get to the definition of a building here. Is a solid pyramid a building or just a shaped pile? As mentioned, the Flatiron building has an iron skeleton. If the building is all brick, how many doors and windows and of what dimensions. In the NYC building code, rooms must have windows to be counted as rooms. There are too many variables being left undefined here.

Subject: RE: BS: How high can a brick building go?
From: Bert
Date: 11 Nov 06 - 01:54 PM

Hey Squeaks, them dung bricks not only sticks better, they stinks better too.

Subject: RE: BS: How high can a brick building go?
From: Crane Driver
Date: 11 Nov 06 - 02:01 PM

You lot should know by now that folk music has the answer to everything . . .

I'll tell you a tale about a man,
A builder he was by trade,
He built a chimney nine miles high,
And all of the bricks he made.
Along came another who said to him,
"I can do better than that,
I'll mix all the mortar and make all the bricks,
As sure as me name is Pat!"
He built it up so high,
It reached beyond the sky,
They had to take a brick or two off,
To let the moon go by.

(from The Captain told the Mate)

So that settles that . . .

Andrew

Subject: RE: BS: How high can a brick building go?
From: The Fooles Troupe
Date: 11 Nov 06 - 08:00 PM

Is that here in another thread in complete version or in the DT? if so a link please, if not, can we have it in a new thread?

Subject: RE: BS: How high can a brick building go?
From: danensis
Date: 12 Nov 06 - 12:33 PM

Many of the old mills and power stations had brick built chimneys, and I can recall one or two that were 200ft high or more. Pity Fred Dibnah's gone to that breaker's yard in the sky, I'm sure he would have known the answer.

Subject: RE: BS: How high can a brick building go?
From: Crane Driver
Date: 12 Nov 06 - 04:25 PM

'The Captain told the Mate' is here

Andrew

Subject: RE: BS: How high can a brick building go?
From: frogprince
Date: 12 Nov 06 - 04:39 PM

--" trying to order a hot dog took me over an hour."
"YEAH. You were in the lineup for the washroom."

Standing in the men's room lineup, trying to order a weenie, with a translation problem; that's one frightening scenerio!

Subject: RE: BS: How high can a brick building go?
From: Peace
Date: 12 Nov 06 - 04:42 PM

Especially if you have to use hand signals . . . .

Subject: RE: BS: How high can a brick building go?
From: Scotus
Date: 12 Nov 06 - 06:17 PM

"It really depends on how much explosive you use"

I used to lecture in a tech college and our gas engineering lecturers described the strength of an explosion as '1,000 bricks' or '10,000 bricks' etc.

Jack

Subject: RE: BS: How high can a brick building go?
From: GUEST,Dazbo
Date: 13 Nov 06 - 04:59 AM

Sorry not to have replied earlier but I've been out all weekend at melodeon workshops in Witney (but today is a nice day for kite flying).

Thanks for the info (and the smiles)

Subject: RE: BS: How high can a brick building go?
From: Liz the Squeak
Date: 13 Nov 06 - 06:24 AM

Hey Gervase, you're not lining another chimney with sh!t again are you?? You promised I could help next time!!!

LTS

Subject: RE: BS: How high can a brick building go?
From: jonm
Date: 13 Nov 06 - 06:45 AM

A simple stack of bricks could go to about 340m before the lowest are in danger of compression failure, based on compressive strengths given below, unchecked. As stated below, the mortar is generally stronger than the brick.

This presupposes that the foundation is inflexible - any movement will put all or part of some of the bricks into tension and you will have cracking almost immediately.

It would be very difficult to construct a brick building more than five conventional storeys high without internal structural bracing. Conventional houses have floors which are laid onto joist hangers; once the structure goes above three floors, there is a requirement for internal bracing so some of the floor joists are structural to prevent rotation of the structure or flexing. Small areas in plan, such as chimneys, can go much higher before this becomes a problem.

Openings for windows and doors present opportunities for the structure to flex as well; this is again where bricks and/or mortar joints are placed in tension with reliably catastrophic eventual results.

Subject: RE: BS: How high can a brick building go?
From: Liz the Squeak
Date: 13 Nov 06 - 06:54 AM

Lego towers only go so high before they start to bend... then they smash to the floor in a satisfying manner whereupon there will be at least 4 bricks that go under the piano, 19 under the table, 3 where they can't be found except by bare feet and one that is never seen again. You can always guarantee that this one is the one you require to build Hogwart's Castle and no other brick can replace it.

LTS

Subject: RE: BS: How high can a brick building go?
From: Paul from Hull
Date: 13 Nov 06 - 07:02 AM

Paul B, & Mr McGrath,

Though not the size of a Cathedral, its as big as a Minster, & brick-built:

Holy Trinity Church (scroll down page for links to pics)

...its the largest Parish Church in England.

Subject: RE: BS: How high can a brick building go?
From: Bunnahabhain
Date: 13 Nov 06 - 08:11 AM

That does depend somewhat on your definition of a storey, Jonm.

New houses/flats in this city are built with the standard 7'8"(ish) ceilings, where as the Georgian and Victorian ones next door are in the range of 12-15'
They're all assorted masonry, so the same structural problems exist.

Subject: RE: BS: How high can a brick building go?
From: Rapparee
Date: 13 Nov 06 - 08:31 AM

So, what about adobe bricks? Some of those buildings in places like Mesa Verde are pretty high for unkilned mud bricks.

Subject: RE: BS: How high can a brick building go?
From: Bunnahabhain
Date: 13 Nov 06 - 09:06 AM

Using a selection of values pulled from research papers, an Adobe column will give way at the base at about 11m.

This is for well made, average bricks, without straw re-enforcement.

Tapering Walls, and ignoring the building codes would allow you to go alot higher though. The steel re-enforcement Earthquake codes force people to put in buildings may work in standard masonry, but actually weaken Adobe....

Subject: RE: BS: How high can a brick building go?
From: Rapparee
Date: 13 Nov 06 - 10:58 AM

Hmmm...the buildings at Mesa Verde are braced against cliff walls. Those at Hovanweep and Chaco stand alone. Eleven meters, huh? I'm going to have to research some of the California missions, as I think they are more than 11 meters, but then they might be stone.

Subject: RE: BS: How high can a brick building go?
From: gnu
Date: 13 Nov 06 - 02:43 PM

Well, I'd say this one had just about been trowelled to death.... I'd say the hod is empty... I'd say the wake is over (Tim Finnegan's)...

Soooooo.... How high can you pile a cohesionless homogeneous material consisting of particles of uniform gradation upon a structure such as pile supported marine dock of infinite area and infinite vertical load bearing capacity?

For instance, say you were stockpiling sand on a wooden wharf. You know that the wharf can easily handle a vertical load of a thousand truckloads of sand but, when the 500th load goes on top of the pile, it's goodbye wharf. How did the wharf fail?

John is disqualified from answering this one as it is one of the most common modes of failure analyzed in structural and soils engineering.

Ah... if this is a stunned question, er, ah, not appropriate, ignore it. I just think it's cool. But then, I AM a beaver, damit!

Subject: RE: BS: How high can a brick building go?
From: Bunnahabhain
Date: 13 Nov 06 - 06:01 PM

How high can you pile a cohesionless homogeneous material consisting of particles of uniform gradation upon a structure such as pile supported marine dock of infinite area and infinite vertical load bearing capacity?

For instance, say you were stockpiling sand on a wooden wharf. You know that the wharf can easily handle a vertical load of a thousand truckloads of sand but, when the 500th load goes on top of the pile, it's goodbye wharf. How did the wharf fail?



I don't know the answer to this, but there are a couple of lines to go down:

How much will the Wharfs foundations hold? And the ground they're on?

How regular are it's piles? If they're several hundered meters apart, then it doesn't matter how strong they, but it does matter how strong the deck is.

Subject: RE: BS: How high can a brick building go?
From: gnu
Date: 13 Nov 06 - 08:05 PM

"How much will the Wharfs foundations hold? And the ground they're on?"... as stated... infinite vertical load bearing capacity.

"How regular are it's piles?"... as regular as you want.

If they're several hundered meters apart, then it doesn't matter how strong they, but it does matter how strong the deck is".... ahhh, yes, but I think you may be thinking in the wrong direction.... reference your first question. The foundations and ground can, by definition in the original poser, bear an infinite vertical load.

Subject: RE: BS: How high can a brick building go?
From: The Fooles Troupe
Date: 13 Nov 06 - 08:18 PM

hmmm, didn't take first time...


"The steel re-enforcement Earthquake codes force people to put in buildings may work in standard masonry, but actually weaken Adobe.... "

An Aussie has recently invented a cheap and simple method for tying together mud very low level structures using locally found materials - bamboo and fencing wire - this technique is being used in rebuilding in the recent earthquake and tsunami zones to the north of Australia, and I think perhaps elsewhere in the world.

It is just intended to hold the building together long enough so that people can run outside before the roof falls on them and kills them. It has been tested on 'shake tables' - think it even made it onto the ABC (Oz) TV program 'New Inventors' this year or last.




"a cohesionless homogeneous material consisting of particles of uniform gradation upon a structure such as pile supported marine dock"

In a practical case - i.e. non infinite area, the sand will spill over the edge, so the height is limited by the 'slippage factor' (I'm not a qualified engineer, so I don't know all the 'real terms'), which any engineer should be able to tell you - there is a critical angle for each material.

Subject: RE: BS: How high can a brick building go?
From: Rapparee
Date: 13 Nov 06 - 10:24 PM

Where the heck do you find a cohesionless material? Even in zero G each particle would exert a minute gravitic attraction upon each other. Unless your material doesn't have mass, of course. Then it would be pure energy, and I don't think that energy HAS a gravitic attraction. Come to think of it, does gravity attract gravity?

Subject: RE: BS: How high can a brick building go?
From: The Fooles Troupe
Date: 14 Nov 06 - 12:22 AM

"cohesionless material"

Ah - Trick Question!

The answer to 'critical angle' above is thus zero - all of it will spill over a practical surface, or spread infinitely out - sorta like one' dem 'SF Horror Movies'...


Another interesting thread of investigation...

"pile ... particles of uniform gradation upon a structure such as pile supported marine dock"

The 'Average weight' over the whole thing is just that - in the middle of the pile (assuming a 'critical angle' of greater than zero!) the greatest actual weight will be where the resultant slumped pile is highest - in the centre.

The 'average strength' of the dock doesn't matter - just where the greatest stress is - 'the weakest link in the chain' thingie...

Subject: RE: BS: How high can a brick building go?
From: gnu
Date: 14 Nov 06 - 06:41 AM

Cohesionless... like sand. Sand will pile up, and, yes, there will be a particular angle (the angle of internal friction which is dertermined by the "slippage factor" between the particles as Robin has mentioned) to the exterior of the slope.

An example of a cohesive material would be clay, as in, say, a clay brick.

Seems like few people are interested in this, so I'll spill the beans now

In addition to the "slippage factor" ("friction factor") within the sand pile, there is a friction between the sand and the dock. This friction exerts a tensile force on the dock acting from centre of the plie toward the edge of the pile. When this tensile force exceeds the tensile strength of the dock, the dock is pulled apart in the horizontal direction.

Failure analysis is some cool, eh?

Subject: RE: BS: How high can a brick building go?
From: The Fooles Troupe
Date: 14 Nov 06 - 07:16 AM

"the dock is pulled apart in the horizontal direction"

which is what I suspected - the 'infinite vertical' thing was a lead - just didn't get around to working it right thru in words.

But if the dock is infinite, then there would be no problem.... :-P

Subject: RE: BS: How high can a brick building go?
From: gnu
Date: 14 Nov 06 - 08:48 AM

Apart from the big hole in the middle, I suppose not.

Subject: RE: BS: How high can a brick building go?
From: Charley Noble
Date: 14 Nov 06 - 08:51 AM

If all the young ladies were bricks in a pile,
I'd be a mason and lay them in style!

Cheerily,
Charley Noble