What's Going On In Texas? Part 2

[msquared48]

Sounds real fishy here, and it's not due to global warming.

I'm wondering if the soils investigation may not have gone deep enough to discover either a very localized, highly compressible region under the tower. Or it could be vibrations in the tower area from the construction, or otherwise, causing a quick condition under the tower. Just conjecture though.

If the tower is just settling straight down and not leaning, what is the problem causing the need for demolition? After all, the leaning tower of Pisa is still standing... Just seems like the state of Texas is too swift far too often to throw the switch when it comes to eliminating problems.

Isn't there a lot of sand in the gulf islands to contend with?

Mike McCann
MMC Engineering

 

[hokie66]

According to the ENR report, the building is on 95' long grout injected piles in sand, recommended by the geotech based on an investigation stopping at 100'. Compressible clay started at 120'. What would be the normal depth of investigation for a 31 storey, say 300' tall building?

http://enr.ecnext.com/coms2/article_bubt091007SouthPadreTo

 

[rowingengineer]

According to Das 150-250ft for a 300 ft tall building, and what I use for my minimum requirements. But it would also depend on the local expectations/equipment.

I would find it unusual that this clay layer wasn’t know about by the local geotechs, normally they would have a good idea of the expected conditions.


Arguing with an engineer is like wrestling with a pig in mud. After a while you realize that them like it

 

[rowingengineer]

sorry pressed enter before the gramma check.

Arguing with an engineer is like wrestling with a pig in mud. After a while you realize that them like it

 

[Drumchaser]

More ramblings.......

I am not sold on the design/build concept at this time, I think it erodes objectivity and monitoring.

I have also never been a fan of a GC hiring/paying for in feld testing/inspection.

While this mess could very well be attributed to poor geotechnical/design, I would be looking hard at construction records, quantities, weather, credentials, diaries etc.

If the guys on the ground do not exercise due diligence at all times, the geotech stuff is meaningless.
This would not be the first time I have seen folks get in too big of a hurry to do things correctly.

 

[structuresguy]

Do 16" diameter, 95ft long auger cast piles seem a bit too skinny to you guys? I have done many jobs with 16" (and 14") ACP's, but never longer than about 60 or 70 feet. 95 feet seems really long to me. Also, for a building that large, I would think larger piles or drilled piers should have been used. Personaly, I don't think I would have wanted to use anything less than 24" diameter.

 

[JStephen]

"Datum disputes a substantial amount of the allegations in the petition..."

IE, it's hard to tell what's going on from a news story which is based on the petition filed.

The clay issue could be as simple as a statement in the report saying "There's probably a clay layer down there, we should drill deeper and find it."

 

[RacingAZ]

I'm skeptical of this lawsuit. It's like throwing the baby with the bath water type of action with the demolition that they are trying to do instead of trying to engage the original designers or hiring new designers to come up with a solution to save the building.

Why? The developer's market is currently dead so going forward and finishing the project would result in more losses. Note the claim for $125M in damages instead of the amount to get the building fixed. The economics right now of the project does not make sense so for the developer, it's better to just demolish the building and claim the losses against the designers. Even the developer admitted this in the article. That's where I have a problem with. That $125M claim is probably for the cost of the construction so far and if they get awarded near that amount, the designers pretty much paid for the unfinished building and do not get to keep the building?

I can't comment about the culpability of the designers as I don't have any data to make an opinion either way but I hope the judge will order this case to mediation and see thru the developer's tactics. The defects might as well be valid but they are being used as an excuse to kill the whole project and recoup some of their investments when I think the market economics is the one driving it all along.

 

[80smetalfm]

I used the same pile size for a 3 storey building and twice that size for a 10 storey building. Those piles adopted sounded too small in my view unless if they were spaced at every 48 inch!

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