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"Doomed" Las Vegas Tower - Structural Blunders 17

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Be interesting to get a copy of the drawings... just to see what is not 'constructable'... coincidentally, I understand that the unemployment in LasVegas is in excess of 20% and that things have ground to a halt in that town.

Dik
 
Wow, sounds like a culmination of errors committed by multiple parties.
 
Having read this article, I would say the majority of the fault lies jointly with the steel erectors and the third-party inspection company.

The steel erectors should have notified the general contractor, who wouold have thus notified the structural engineer and maybe something could have been worked out, rather than just not istalling the steel anchor supports.

And shame on the third-party inspection company for falsifying all of those reports. Sixty-two falsified reports, where one falsified report is unacceptable.

However, this will be backlashed onto the structural engineering company, and the argument is going to be that they supposedly never visited the project site to perform simple progress check-ups.

All-in-all it will be interesting to see how this whole thing gets resolved.
 
ABP...as is usual. In construction failures, there's rarely one culprit. In many projects that get built, they do so in spite of the three main parties...architect, engineers, contractor!

In 34 years, I have yet to find a flawless construction project.

This one will be litigated for a long, long time.

Thanks for the post, JAE.
 
I won't post a link here, but if anybody wants to look at the credentials of the third party inspectors, you may wonder as I do why a firm of geotech and materials engineers were appointed as structural inspectors on a complex concrete highrise.
 
Call me crazy but I always like to have the guy who designed the building also to be the inspector. stuff this third party situtations.

ANY FOOL CAN DESIGN A STRUCTURE. IT TAKES AN ENGINEER TO DESIGN A CONNECTION.”
 
62 falsified reports is disgraceful and negligent. Thats the type of corruption I would expect to see oversee's but not in the US. They should throw the book at everyone. The builder, the inspecting engineer, the building certifyer and anyone who was aware there was dodgy practices going on and didn't say anything..

I guess it's okay that this negligence has only cost a property developer a couple of hundred mil US, but this could have cost someone their life.
 
rowingengineer,

I do agree with your statement, but unfortunately that could be perceived as a conflict of interest on some level. Especially if you have to follow Chapter 17 of the IBC, a third-party "special inspector" is required.

kikflip,

Unfortunately, the ones who will get the brunt of it will be the structural engineer and the general contractor. Most third-party inspection companies aren't really large enough to provide some sort of back-pay and face any level of fines...and usually fold right away to cover the inspector's owners and professional engineers...if they even have any professional engineers on staff to oversee the inspection crew.

Just my general opinion on this whole matter.
 
We have had this discussion about third party inspection before. I don't know what is so special about "special inspectors", but it seems to be popular among US engineers these days (not when I worked there). Like rowingengineer, I think it is a detestable situation.
 
"Special" inspectors are not very special afterall. I have countless stories of negligent/incompetent/"I don't care" special inspectors on projects that I have designed/worked on.

I don't believe there to be a conflict of interest. I don't think that we structural engineers are so negligent that we will let something slide by just because we are also the engineer-of-record. If there is a team of people that know the project inside-out, it is the structural engineer.

We do a lot of our own inspections in South Florida on Threshold projects. Our office policy is such that the person who designed the project (project engineer) is not the person doing the inspections. The inspector is someone within our own office (an EIT with 2-3 or more years of experience) who has strong engineering knowledge but no project knowledge. The goal is to inspect what is on the drawings and also sometimes to question "suspect" details and discuss it in the office.

I believe we strive to make our structure as safe and as constructable as possible. It also helps the project go smoother because there is always a direct line of communication between the "design team" and the "inspector" which is not often the case when you have "third-party" inspectors who have to follow round-about protocols to get problems corrected or questions clarified.

Enough of the rant, IMHO I think the third-party inspections is bogus.

 
I agree with almost everything that slickdeals says above.

I see no conflict of interest for this type of thing - we are not awarding contracts only ensuring that the building is safe. If it is safe no problem, if it is unsafe then it is the engineers door that will first be knocked on.

I am a strong advocate of the person who designs the building doing the inspection for a couple of reasons.

Firstly, it gives a direct route for important feedback and learning. How is a graduate engineer expected to get an understanding of what works or doesnt work on site unless they are involved in the inspections.

Secondly, there is no such thing as a perfect design. Any flaws are much more likely to be picked up on site by an educated pair of eyes that understand the way the building is designed to work.

Lastly, they are probably the most appropriate person for the job.
 
I know (and used to work for quite some time ago) the structural engineering firm named in the world architecture news article They have a significant history of technical expertise on large, complex projects around the world. I don't know any details of this project other than those in the article.

In my experience, complex details need to be worked out at the design stage and sometimes the design intent may not be clear to a contractor or an inspector (3rd party or not) who is not intimately familiar with the intent of the details. I have witnessed how much work has gone into complex rebar layouts at the design stage with 3D models and such to try and assess constructibility. There have been instances I have been involved where contractors and inspectors, under the pressure of time and $$$ (or through lack of training), make subtle field modifications, that on the surface appear reasonable, but create conflicts with the original design intent. I am a big fan of keeping the EOR informed of ANY design changes in a timely fashion. Sixty-two falsified reports is totally unacceptable and misleading.
 
First of all, Las Vegas has a system for qualifying special Inspectors. It's actually more rigorous than most. This really discourages firms from performing their own Special Inspections, which I believe was the intent of the code.
The VP of the Special Inspection firm has had his license suspended by the State of Nevada. We've worked with them, as a Geotechnical Firm, extensively. I've met him. He's a good man and a good engineer. I'd sure like to hear his side of the story.
 
Our firm has not performed special inspection services before but we have worked with third-party inspectors before on the projects that we have designed. We do perform regular site visits to follow progress, answer contractor questions and address constructability concerns.
I will say that communication is key and it is imperative that inspector qualifications be reviewed by the owner and design team.

I'm not totally opposed to third-party inspectors as they have been very helpful and the special inspection process can be very time consuming. The third-party guys that I have worked with have been very active in the problem solving process when issues arise and I have learned a lot from them and the contractors for that matter.
 
Having the special inspectors work for the EOR is infinitely superior to having a third party inspector. The EOR is “in the loop” when inspections are scheduled through his office, he can track the progress, notify the inspector when critical-complicated items will be coming up, he will see the reports in a more timely manor and there is a direct line of communication between the inspector and the EOR.

From personal experience, whenever I have a third party inspector on one of my jobs, I almost never get any calls from the field or comments on the reports that they found anything to be non-conformant. When my own people do these inspections, I get multiple calls every week asking if something is OK, or if something needs to be fixed.

Sophisticated owners recognize the value of having the inspector work for the EOR, but all to often, they see the bottom line and go with the low-ball number. Many just don’t understand the impact of using an un-certified concrete tester as their inspector.

Perhaps projects like the one highlighted in this thread will wake some people up- but I doubt it.
 
I believe the EOR has always been able to act as the approved agency for special inspections. (I do not have my 2003 or 2006 IBC handy.) The IBC 2009 section 1704.1 has been changed to read “...The registered design professional in responsible charge and engineers of record involved in the design of the project are permitted to act as the approved agency and their personnel are permitted to act as the special inspector for work designed by them...” No doubt to clarify the issue.

Garth Dreger PE
AZ Phoenix area
 
As with most articles in non-professional magazines, this seems to jump to lots of conclusions without even trying to understand the full story. A complete peer review of the original design and an extensive as-built survey may be necessary to come to any reasonable conclusions about what is wrong with this structure. But that makes for a technically accurate but boring article.

And why would a steel structure ever need to be demolished if there are structural problems? You can modify a steel structure in an infinite amount of ways once its built, I imagine at a fraction of the cost of demolition and rebuilding.

Special Inspection- Though I like the idea of in-house special inspection (done by the EOR), that is not always logistically feasible. If the project is 2+ hours away and you are a one or two man SE firm, occasional observations may be the only service you can provide. Second, many E and O insurance policies specifically exclude INSPECTIONS without a modification to your policy.
 
@a2mfk

The structure in question is CIP concrete. The deficiencies were in rebar.
 
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