Earthquake resistance: Linear, or not...? - Page 4

>
>>.
>>
>>>
>>>>The word that you are looking for is Ductility not flexibility.
>>>>Such as a
>>>>ductile moment frame. Hope this answers the question.
>>>>
>>>Sorry, Chuck but this thread is on earthquakes - the AC duct
>>>relocation question is a couple threads over. ;)
>>>Don is always looking for a word - and he's going to use every word
>>>he knows until he finds it. =:O
>>>R
>>>
>>Both ya'll need to pay attention, I didn't use either of those words,
>>I think Kris did, about bones.
>>
>Yup, I did. Bones are felxible. Wood is flexible.
>Flexible = able to bend without incurring damage
>Ductible = capable of being drawn out
>A spring is flexible. The metal that is drawn out to create the wire used
>to make the spring is ductible.
>
>>But yeah, if Cuse manages to move that thing successfully it could be
>>said he has ductibility. =D
>>
>Or, living near all tat wter in Miami, maybe "ducktability" ;)
>

>

>
>>> .. .
>>>>> The word that you are looking for is Ductility not flexibility.
>>>>> Such as a
>>>>> ductile moment frame. Hope this answers the question.
>>>> Sorry, Chuck but this thread is on earthquakes - the AC duct
>>>> relocation question is a couple threads over. ;)
>>>> Don is always looking for a word - and he's going to use every word
>>>> he knows until he finds it. =:O
>>>> R
>>> Both ya'll need to pay attention, I didn't use either of those
>>> words, I think Kris did, about bones.
>> Yup, I did. Bones are felxible. Wood is flexible.
>> Flexible = able to bend without incurring damage
>> Ductible = capable of being drawn out
>> A spring is flexible. The metal that is drawn out to create the wire
>> used to make the spring is ductible.
>>> But yeah, if Cuse manages to move that thing successfully it could
>>> be said he has ductibility. =D
>> Or, living near all tat wter in Miami, maybe "ducktability" ;)
>
> I moved a duct today and used the method Rico said, I moved it
> upstream about 2 feet.

> I used *duct* tape to seal it against the register then I put a giant
> zip tie over the whole mess.
> Believe it or not this house has heat-AC registers in the floor, and
> the one in question was right where you will step out of the new
> shower, so it had to go.

> I was going to originally move it up high on the wall but the actual
> doing was much more than I could deal with.

>
>>> [Edited]
>>>>> As far as earthquake stuff goes, my knowledge is
>>>>>> limited to general science stuff I've seen on the toob but I
>>>>>> believe flexibility is the key.
>>>>> Felxibility, yup, that does seem to be a main, or poss. *the*
>>>>> main, point. I saw one thing (let's face it, if thre is somehting
>>>>> on about earthquakes, i watch it...) which showed buildings in
>>>>> Turkey - new houses that were monolithing construction
>>>>> (cinderblock) fell apart, btu traditional houses, which started
>>>>> with timber frames taht included diagonal supports (not so
>>>>> differnt from old ENglish half-timber methods), which then were
>>>>> filled in with bricks, remained standing, with only a rew
>>>>> exceptions.
>>>>> Your point re: the trusses is also a good one. So, yup, it seems
>>>>> that a building has to be a *system* to survive unusual
>>>>> conditions, as opposed to merely being a collection of disparate
>>>>> parts...
>>>>> Let's hear it for cells (as in the biological/living things) ;)
>>>>> Actually, only half a joke - are you catching any of the new
>>>>> series about the Body?
>>>> No, but I'm going to.
>>>> (short story: My wife and I have gotten into the habit of watching
>>>> that show, 'How It's Made' on Discovery while eating supper and
>>>> invariably they'll show a commercial about 'The Body' and eveytime
>>>> they do I say, 'One of these days I'm gonna watch that show'. Its
>>>> sort of a joke. So far I haven't watched it. We don't watch much.)
>>> Both are intresting, although sometimes the "how it's made" topics
>>> are less interesting to me than teh biology-related things - such
>>> as, I wasn't fascinated with how pencil erasers are made ;)
>>> Mechanical topics are interesting, tho'.
>>>>> Last week, they discussed bones, and the high degree to which
>>>>> bones are cellular is structure (as opposed tosolid) and
>>>>> *flexible* - it was maazing to see how far a bone could bend
>>>>> before failing (breaking). Biology has had millions of years to
>>>>> "experiment" and offers intersting examples. Makes me wonder
>>>>> whether,a t some point, we'll be able to *grow* buildings -
>>>>> although that's an entirely different topic.
>>>> According to Per Corel that exactly how its going to happen, sort
>>>> of. He envisions his 3DH buildings constructed at the molecular
>>>> level by microscopic robots and after a building is completed the
>>>> robots will be reprogrammed to perform constant maintenance.
>>> THe problem is that I never could get a handle on what "3DH"
>>> actually *means*. I also never caught the bit about the
>>> mini-robots, either, so thanks for pointing that out... I had a
>>> hard time understanding the explanations. I looked at the pics of
>>> models, but i guess I didn't get out of them what was intended...
>>> Anyway, re: "grow buildings", I mean, biologically, not using
>>> robots. More along the lines of breeding a tree, for example, that
>>> stays under a certan height, and grows in a way that creates hollow
>>> chambers. Not even my own idea, really, but somehting I came across
>>> in a "scifi" novel.
>>>>> Meanwhile, the interactions between materials, and structures, and
>>>>> the resulting resistance to stresses, is an interesting thing.
>>>>> I'm thinking that the "weaklink" in wooden structures, as far as
>>>>> earthquake resistance goes, might be the nails, since wood itself
>>>>> seems far superior. SO I'm wondering whether it'd be "sturdier"
>>>>> (to use the term a bit inaccurately but hopefully the meaning is
>>>>> clear) to use fitted joints, as were used in the "pre-nails"
>>>>> days...?
>>>> Here's a prediction, which I originally predicted some 10 years
>>>> ago. Under the right conditions the wood trusses will fail because
>>>> the number of nails required will effect the stability of it.
>>> Not surprising - the strength and flexibility of wood, like that of
>>> bone, is not a funciton merely of the existence of verious types of
>>> cells and "biological glue" so to speak, it's a funciton of the
>>> *interconnectedness* of the cells and any other materials. THink
>>> abotu the qualities of cartelege, and then think what would happen
>>> if it were punched full of holes. People think of wood as "hard",
>>> more than they think of it as "flexible", and same is true of bone.
>>> But part of the strength *is* the flexibility, and that flexibility
>>> is comprimised once the material is made discontiguous so to speak.
>>>> Right now, something like 18 nails are *required* at each
>>>> truss/hurricane anchor and to me that many holes in the wood isn't
>>>> a good thing. Ever seen a piece of wood with 18 nails in close
>>>> proximity? It ain't pretty - the wood is horribly splintered.
>>> Yes, and true.
>>>> I'd rather see 12 guage angle steel reheaded into the top/side of
>>>> the concrete tiebeam and through bolted through the truss heels -
>>>> the angle steel would go up and over the top chord and be bolted
>>>> from both sides. This would be less strain on the wood in the
>>>> truss. The plywood roof sheathing, not OSB, 3/4" plywood, would be
>>>> installed with #12 x 3" screws @ 8" o/c along the perimeters of the
>>>> sheets and all plywood seams would receive 2x4 deadwood. These
>>>> things would add about 15-20% to the cost of the roof but would add
>>>> considerably to the overall integrity of it. **No inspector is ever
>>>> going to count all the nails in every hurricane anchor on every
>>>> house.
>>> Hmm. Interesting idea. I'm saving that one.
>>> ((Isn't the largest cost of most houses actually the land, rather
>>> than the structure...?))
>> Probably the most expensive single piece of land I've been involved
>> with was $850k for less than 1/4 acre on Useppa Island and the house
>> that was built on it was valued at over $2 mil.
>> Most of the stuff I've done was a far less ratio.
>> My own property in the Cape cost $3500 in 2001 for 1/4 acre and in
>> 2006 I sold it with a house on it for $300k and the original cost of
>> the house was $155k + add-ons.
>
> The word that you are looking for is Ductility not flexibility. Such
> as a ductile moment frame. Hope this answers the question.
>
> CID...
>
>

>>>>
>>>I know the Richter scale is exponential, but I'm still wondering
>>>whether a structure builkt to withstand X.Y fails at X.Y+1. So, they
>>>aer currently retrofitting the Golden Gate Bridge to withstand
>>>soemthng like 8.3, but does that mean it will fail (i.e.
>>>disintegrate) at 8.4, or what?
>>>
>>Can't be done, except in a computer model, cause there's too many
>>variables. First, you have to define *failure* then design around that
>>parameter. In SW FL for example the homes I design are supposed to
>>sustain a 130 to 150 mph wind and usually they do.
>>But that doesn't mean things won't fail.
>>
>SO, if it's designed to withstand 150mph, and a 160mph wind occurs, the
>whole thing simply disintegrates instantly...?
>What I'm trying to figure is, if people are in a bldg (house, highrise,
>whatever) rates to withstand X.Y, but a quake of X.y+1 occurs, does the
>bldg just completely disintegrate/implode into shards at that point and
>kill everyone inside?
>

>
>>On my own house, it went through several hurricanes but some things
>>did fail, though nothing structural.
>>If any of those hurricanes would have stalled on my house there very
>>well may have been structural failure.
>>Some of the soffit tore loose, a design flaw (which was later
>>corrected), that allowed wind to penetrate the envelope.
>>If this wind would have sustained it may have lifted that portion of
>>the roof and once that happens its all over.
>>(I installed more, and longer, nails along the edge of the fascia that
>>attaches the soffit and used 24 tubes of silicone caulk to secure the
>>soffit to the stucco wall and fascia. This had the added benefit of
>>thwarting the yellow jackets from nesting in the valleys of the
>>soffit) Regarding the Golden Gate, what did they do, put it on pulleys
>>so it'll sway like a pendelum?
>>
>I couldn't really teel from the program - in many areas, it looks like
>they're reinforcing it, but I don't knw whether other areas might be put
>onto rubber "floats" - I couldn't tell. But San Francisco (IIRC) has
>been literally lifted and placed onto rubber plugs that are supposed to
>absorb the shaking. THey also described the swaying that some wooden
>houses can withstand.
>So that's what all got me wondering about building for earthquake
>resistance, and what the limits of that are.
>I'm not sure I asked the question properly, either.
>

>