Passive Earthquake Proofing w/ Dry Stone

[Bret Cahill]

http://en.wikipedia.org/wiki/Earthquake_engineering#Friction_pendulum_bearing

"People of Inca civilization were masters of the polished dry-stone
walls, called ashlar, where blocks of stone were cut to fit together
tightly without any mortar.

.. . .

"Peru is a highly seismic land, and for centuries the mortar-free
construction proved to be apparently more earthquake-resistant than
using mortar. The stones of the dry-stone walls built by the Incas
could move slightly and resettle without the walls collapsing which
should be recognized as an ingenious passive structural control
technique "

 

[John Larkin]

On Mon, 10 May 2010 07:52:45 -0700 (PDT), Bret Cahill
<BretCahill@peoplepc.com> wrote:

Damping must be pretty effective. Look at how many resistors they use
in electronics . . .

Only a small minority of resistors are used for damping. In most
products, none are.

John

 

[john]

On May 9, 8:54 pm, Bret Cahill <BretCah...@peoplepc.com> wrote:

http://en.wikipedia.org/wiki/Earthquake_engineering#Friction_pendulum...

"People of Inca civilization were masters of the polished dry-stone
walls, called ashlar, where blocks of stone were cut to fit together
tightly without any mortar.

. . .

"Peru is a highly seismic land, and for centuries the mortar-free
construction proved to be apparently more earthquake-resistant than
using mortar. The stones of the dry-stone walls built by the Incas
could move slightly and resettle without the walls collapsing which
should be recognized as an ingenious passive structural control
technique "

But were they cut?
I've heard that story before.
It's hard enough to get a simple floor edging
cut once to fit together around a corner-
if the floor is tilted any way at all wrt the wall,
you add in that 3rd dimension and things get
*much* harder.

I liked the trapped miner's story about
the blocks being poured in place. Some
kind of nano-concrete that sets up like stone.

I also had a dream about large buildings-20-30 floors-
whose entire sides were murals of various kinds.
And the pixels making up the picture were cut
stone blocks of different colors. But these
blocks were highly regular, like cut by laser or something
(magnetically separated?)

john

john

 

[Bret Cahill]

http://en.wikipedia.org/wiki/Earthquake_engineering#Friction_pendulum...

"People of Inca civilization were masters of the polished dry-stone
walls, called ashlar, where blocks of stone were cut to fit together
tightly without any mortar.

. . .

"Peru is a highly seismic land, and for centuries the mortar-free
construction proved to be apparently more earthquake-resistant than
using mortar. The stones of the dry-stone walls built by the Incas
could move slightly and resettle without the walls collapsing which
should be recognized as an ingenious passive structural control
technique "

But were they cut?

They had to do _some_ chipping or they would spend all day looking for
the right shape.

I've heard that story before.
It's hard enough to get a simple floor edging
cut once to fit together around a corner-
if the floor is tilted any way at all wrt the wall,
you add in that 3rd dimension and things get
*much* harder.

Maybe you need to chew on leaves to get everything to fit.

I liked the trapped miner's story about
the blocks being poured in place. Some
kind of nano-concrete that sets up like stone.

The plaster fell off after the last quake exposing these great cracks
in the 18" - 2' thick concrete wall structure supposedly from an
earlier quake decades ago. Several tenents vacated within days.

The walls were still plumb / flat / straight and the concrete pieces
still fit together so nicely I wondered if the extra flex from the
cracks might actually be an advantage. Then I read the Inca article
and was reassured even more.

I suggested that the landlord shouldn't replaster. Kind of like post
modern architecture, there's beauty in honesty as well as functional
cracks.

Damping must be pretty effective. Look at how many resistors they use
in electronics . . .

I also had a dream about large buildings-20-30 floors-
whose entire sides were murals of various kinds.
And the pixels making up the picture were cut
stone blocks of different colors. But these
blocks were highly regular, like cut by laser or something
(magnetically separated?)

A 4.5 + will often get incorporated into my dreams except I'm in a 9
story building made of sandstone . . .


Bret Cahill

 

[Bret Cahill]

Damping must be pretty effective.  Look at how many resistors they use
in electronics . . .

Only a small minority of resistors are used for damping. In most
products, none are.

No wonder so many laptops break after you hurl them across the room!


Bret Cahill

 

[Jasen Betts]

On 2010-05-10, john <vegan16@accesscomm.ca> wrote:

On May 9, 8:54 pm, Bret Cahill <BretCah...@peoplepc.com> wrote:
http://en.wikipedia.org/wiki/Earthquake_engineering#Friction_pendulum...

"People of Inca civilization were masters of the polished dry-stone
walls, called ashlar, where blocks of stone were cut to fit together
tightly without any mortar.

. . .

"Peru is a highly seismic land, and for centuries the mortar-free
construction proved to be apparently more earthquake-resistant than
using mortar. The stones of the dry-stone walls built by the Incas
could move slightly and resettle without the walls collapsing which
should be recognized as an ingenious passive structural control
technique "

But were they cut?
I've heard that story before.

Yeah, ball and socket not unlike giant Lego.



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