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By Chris Olbekson on Flickr    

Building 1 has tenants in it but work continues on building 2, I guess perfection takes time. It actually looks good.

IMG_7868 by Andrew Rebman, on Flickr

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On the plus side, perhaps it will compliment the tin homes across the street that look like they fell off of a container ship.

 

Hey, I like my aluminum house across the street from this development. On the other hand, beauty is in the eye of the beholder I guess. :)

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It's not the only one going up in town. Six stories of kindling wood framing seems to be easy enough to do....as long as no one runs a forklift into it (see Swamplot for the results).

 

 

Yeah I saw that on swamplot. I cycled by it this weekend. They were disassembling the structure on sunday. Talk about 'oops'

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Yeah I saw that on swamplot. I cycled by it this weekend. They were disassembling the structure on sunday. Talk about 'oops'

Question for the engineer.

Exactly how high can you build with all wood framing and still maintain structural integrity?

10 stories?

15 stories?

20 stories??

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Question for the engineer.

Exactly how high can you build with all wood framing and still maintain structural integrity?

10 stories?

15 stories?

20 stories??

 

Excellent question. The answer is, higher than you think. In Vienna, Austria there are plans for a 25 stories wooden skyscraper (Link: http://www.popsci.com/next-futuristic-building-material-wood?src=SOC&dom=fb )

 

In the article they cite the following:

 

According to a report from architecture firm Skidmore, Owings & Merrill, a 42-story wooden building is "technically feasible."

 

 

 

Now, in Vienna, theyre doing it for carbon footprint reduction, which, in my opinion for skyscraper construction is small fish compared to the larger problems and industries of anthropogenic climate change, but I digress. If someone asked me to design a tall wooden structure for housing people in a hurricane prone region. I would look at them perplexed and say why!? and then tell them No! Rechlin, cites a great structure that I never knew about. (thanks for sharing that).

 

As a basis of comparison if you'd like the nitty gritty details. A36 Steel for a steel I-beam (Or W-Shape) is going to have 36,000 lbs/in^2 yield capacity (the stress where the steel will start to bend and not revert to its original shape) A concrete column will have 5,000-12,000 lbs/in^2 of compressive strength before catastrophically exploding from overloading. And the steel rebar inside of it will have 60,000 lbs/in^2 yield capacity (in Tension)

 

A Southern Pine No. 2 Dense wood timber: 1,250 lbs/in^2 in compression, and 750 lbs/in^2 in tension. (These values would be adjusted based on certain adjustment factors per the design code). So you can see, that building a high rise out of wood is making life, kind of a head ache for the structural engineer. 

 

There are some Glulam members (http://en.wikipedia.org/wiki/Glued_laminated_timber) that's strength is significantly better (than just normal timber), but you run into fire issues without proper protection. 

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As a follow up to swamp lot story,  (off topic sorry mods). 

 

http://swamplot.com/knocked-knox-st-townhome-brought-down-a-few-floors-yanked-straight/2015-03-16/

 

Looks like they disassembled floor 2 and 3 and "straightened" the first floor out. This is dumb.  If they rebuild that house, without replacing the first floor in its entirety, shame on those housing contractors. Every single nail attachment on the first floor has already been compromised by a lateral deflection of that structure. Not to mention any internal damage to the wood members that they may have overlooked. 

 

Lets just say, unless they rebuild that thing: Do not buy that house. 

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Excellent in depth analysis, Purdue, thank you!

Ok now to follow up.

1) I would NEVER agree to work or live in a wooden structure that high.

2) Like you said, sure you could, but WHY ON EARTH WOULD YOU?

3) That is a death trap of a fire hazard WAITING to happen, we all saw what happened with the all wood Axis apartments on West Dallas:

csBeNzp.jpg

lFeIndA.jpg

^ That was only FIVE stories! Could you imagine a blaze of TWENTY-FIVE stories??!! That would be FIVE TIMES THE SIZE OF THAT FIRE!!!! Imagine being trapped on an upper 24th/25th floor when the blaze raged out of control? F@#K THAT!

4) I work in construction, so I'm familiar with alot of geographical constraints we have here in southeast Texas. For instance, in Europe, cranes that are the same size as mine are only required to have 4x4, 1 1/4 inch thick steel plates to set their outriggers on. But thats because the ground over there is so solid.

Down here in Houston? My crane is required to have 8x8, 3 inch thick steel plates, ON TOP of 8' by 16' wooden laminate mats, FOR EACH OUTRIGGER.

One of the old guys I work with likes to joke that "It's because we're sitting on 6 million years of duck flurf down here!"

My point being, even if its feasible to build these huge wooden structures in other parts of the world, would there be any geographical constraints unique to the Texas Gulf Coast (soft ground, salty sea water in the air close to Galveston, etc) that would prevent anyone from building one of these wooden towers here in our region?

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Excellent in depth analysis, Purdue, thank you!

Ok now to follow up.

1) I would NEVER agree to work or live in a wooden structure that high.

2) Like you said, sure you could, but WHY ON EARTH WOULD YOU?

3) That is a death trap of a fire hazard WAITING to happen, we all saw what happened with the all wood Axis apartments on West Dallas:

^ That was only FIVE stories! Could you imagine a blaze of TWENTY-FIVE stories??!! That would be FIVE TIMES THE SIZE OF THAT FIRE!!!! Imagine being trapped on an upper 24th/25th floor when the blaze raged out of control? F@#K THAT!

4) I work in construction, so I'm familiar with alot of geographical constraints we have here in southeast Texas. For instance, in Europe, cranes that are the same size as mine are only required to have 4x4, 1 1/4 inch thick steel plates to set their outriggers on. But thats because the ground over there is so solid.

Down here in Houston? My crane is required to have 8x8, 3 inch thick steel plates, ON TOP of 8' by 16' wooden laminate mats, FOR EACH OUTRIGGER.

One of the old guys I work with likes to joke that "It's because we're sitting on 6 million years of duck flurf down here!"

My point being, even if its feasible to build these huge wooden structures in other parts of the world, would there be any geographical constraints unique to the Texas Gulf Coast (soft ground, salty sea water in the air close to Galveston, etc) that would prevent anyone from building one of these wooden towers here in our region?

 

 

The fire concern is real and youre right, that building totally got owned. There is a difference though between an incomplete building and a completed building with proper firebreaks, sprinkler system, etc.. In addition, SOME wooden structure can perform quite well in fires. A 2x4 will get owned in a fire for sure. But a 10x10 or 12x12 member will undergo charring on the exterior, which can protect the structural components for a time, giving you a surprisingly decent fire rating. In the codes for wood design there are equations that will give you a fire-rating on particular sized members and wood can be treated as well. 

 

It's a slow monday for me at the office. But for a wooden structure in Houston, Im guessing the biggest problems are less so the soil, and more so, the wind. Houston, per ASCE 7 (see picture: https://i.imgur.com/f2MJY71.png ),is going to have to, per code deal with 120mph-140 mph wind velocity, and the way the calculations break down, is the the taller you go the more wind pressure at higher elevations you get. Now, most of us are familiar with torque. Have bolt you can't get undone? add length to the handle, more torque. Torque is a function of force*distance. Theres another term for that, Moment, and a similar principle applies with buildings. Tall building, more force = more turning moment at the bottom. Based on the foundation design, the soils will normally handle that "Overturning moment", even in Houston. What would concern me (keep in mind I dont design 5 story apartment buildings) is the overturning moments on the framing. On the windward side of the building youre going to have a tension load applied (uplift), and on leeward side of the building you'll have a compressive load applied (downlift). In a heavier building, the 'control' check would be on the compressive side, because the building is heavy enough where "uplift" could never occur. Concrete is super awesome at compression, concrete structures: no problem! Wood structures, are way way lighter. The control check, might be on the tension side. Which gives headaches to the engineers. It's an iterative process though. Soils is less of an issue than a lot of people think of. You go deep enough, drive enough piles, or construct enough piers, you can do a lot with that, even in Galveston. Now your question is, I would opine the biggest geographical constraint for a wooden structure on the Texas Gulf Coast, is wind. Speaking in generalities that is. Thats why, when I see a very tall town house, or tall apartment like this in Houston, my eye twitches a little bit. (funny enough, I own and live in a 3 story house inside the loop). I also should state that I'm simplifying wind analysis big time, for what its worth, wind analysis in my opinion: suuuuucks doing by hand. 

 

I'm not familiar with the EuroCodes. So I looked it up, and the way wind analysis is calculated, appears to be different. On anecdotal look through the eurocodes, it would appear than the US codes are more conservative; which makes sense as North American is struck by higher wind weather events more often (in General). But to be honest, I dont know enough about Eurocodes to really give you a good answer on it. 

 

As for your outriggers, issue. That I did not know. And is quite fascinating. I know when I'm in the field, I like to see all the outriggers on clean, and well upkept laminate mats. What is interesting to me though, is the euro-plate steel being thinner, would technically lower the capacity of the crane in comparison to the American counterparts. Which might be how they get away with not putting the mats down? I'm speculating of course. I tried looking through the IBC (international building code: which is about as international as the world series) to see anything in regards to that but couldnt really. 

 

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As far as I know Purdue, the engineers come out to the job site long before any lifts occur and they do all the soil testing necessary to calculate the correct ground bearing pressure distribution that is necessary per OSHA regulations.

Now on cranes as small as mine (265-500 ton) its not really that crucial, but when you get up to the really big cranes like Mammoets PTC or Deep Souths Versacrane, there is enough math and calculations on the ground bearing pressure paperwork to make William Rowan Hamilton confused.

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As far as I know Purdue, the engineers come out to the job site long before any lifts occur and they do all the soil testing necessary to calculate the correct ground bearing pressure distribution that is necessary per OSHA regulations.

Now on cranes as small as mine (265-500 ton) its not really that crucial, but when you get up to the really big cranes like Mammoets PTC or Deep Souths Versacrane, there is enough math and calculations on the ground bearing pressure paperwork to make William Rowan Hamilton confused.

 

 

Ah yes, the deep south versacrane. I was about 200 feet from the one that went down in 2008 at Lyondell Houston Refinery. 

 

Scary day

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Is it because of the "not made of Bricks", issue, Avossos? ;-)

We all know I'm a fan of masonry. But both renderings were unnattractive. Now the new one is yellow and stucco. Looks really cheap

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We all know I'm a fan of masonry. But both renderings were unnattractive. Now the new one is yellow and stucco. Looks really cheap

I agree. That one in midtown by fiesta still looks incomplete to me.

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