COTA Austin - construction and infrastructure

[hairy_scotsman]

Where did you get the idea that it was short? They lost months of good weather over the issue. Not only the time when the project was on full stop but also time when the project was obviously on the back burner. That period was from July 2011 to December 2011. I'm pretty sure that this time loss is at the core of the cost over run now. No idea what you pay for over time in Texas. Those workers who work through the night and Saturdays will not do this for pocket money. I would not be surprised if it added 25% or more to the original price.

I don't know how much money or time the delays and often overlooked slowdowns have cost, but I believe this is correct in principle. Way back in early 2011 we were being told by people on the ground in Elroy that they'd be going to 7-day schedules and 2 shifts "very soon". For months neither thing happened. A 7 days schedule was only recently implemented, and night work started less than a month ago. This delay in going full-force was one of the reasons we believed since long ago that the real race date would be late in the season.

I think that the relevant point is that while construction may have been delayed (by a month at most), the race itself has been delayed by 5 months. Therefore, the delay can't be blamed for cost overruns.

From what I gather, the primary reason for the increased cost was the additional soil engineering that had to be done to keep the track from looking like Elroy road in two years.

During the long slowdowns, they were losing time even while technically "working" on the site. From the outside it's difficult to quantify, but I'm sure someone knows exactly how much time was lost. I believe that before the slowdowns and delays they were indeed at or close to the desired timetable based on a November race, thus the apparent lack of urgency we witnessed, even well earlier in 2011 before the November date was announced.

And I think it says something about the owners and their dedication to the project that they are willing to put more money in the project if it needs it. They basically dug a big ditch and buried $100 million in it, and you don't do that unless you're committed to doing the job right and seeing it through. Maybe some other F1 venues, like China and Brazil, should pay attention.

I hope so. We'll see.

[hairy_scotsman]

I'm curious to see how much the track will be raised, if at all, from where it is now. It seems at the moment like the whole thing is bounded by retaining walls. Which could actually be interesting, imo.

It's all going to be raised back to the level of the surrounding soil and have full asphalt and (I think?) gravel runoff areas. That's part of the engineered design to account for the unstable soil you mentioned.

[Pup]

That's my assumption, but then there are quite a few permanent retaining walls already being built. At least, I assume that they're permanent - in the photos, they look like stacked stone, which seems temporary, but then again, it's stacked finished limestone, which I assume isn't cheap even in Texas. I know we pay a lot here for Texas limestone, but maybe it's cheap enough there to use as riprap?

[WhiteBlue]

I think that the relevant point is that while construction may have been delayed (by a month at most), the race itself has been delayed by 5 months. Therefore, the delay can't be blamed for cost overruns.

That figuring is simplistic. The race delay of five months was immediately figured into the building schedule when it became known. But obviously they did not pick up the pace in time to avoid overtime now.

From what I gather, the primary reason for the increased cost was the additional soil engineering that had to be done to keep the track from looking like Elroy road in two years.

Quite unlikely considering that the very first thing they did was proper profile drilling. They knew the earth mechanical situation in February 2010. If you know a thing about track construction you can budget the necessary supporting layers that would be applicable for any track that requires the smoothness of an F1 circuit. No big difference between Turkey, India or Texas.

They basically dug a big ditch and buried $100 million in it, and you don't do that unless you're committed to doing the job right and seeing it through. Maybe some other F1 venues, like China and Brazil, should pay attention.

I really see no difference to other dry venues as mentioned. That you mention China here shows that you are not aware of the water factor on cost. The Chinese track was build in a swamp which was stabilized with a years supply of all Asian Polystyrene foam. It cost an arm and a leg to sort this place. They were still making improvements to it last year at the tune of $100m.

[hairy_scotsman]

That's my assumption, but then there are quite a few permanent retaining walls already being built. At least, I assume that they're permanent - in the photos, they look like stacked stone, which seems temporary, but then again, it's stacked finished limestone, which I assume isn't cheap even in Texas. I know we pay a lot here for Texas limestone, but maybe it's cheap enough there to use as riprap?

That wall lies between the track areas of Turn 2 and Turns 17-18 and retains the earth there, not the track. Here's a photo I shot on the 14th:



ETA: BTW, the wall is very thick concrete & stone, but I can see how it looks like stacked stone in distant photos. I found a photo that shows it better (from COTA's FB page). The mortar isn't even dry in this shot:

[Pup]

That's my assumption, but then there are quite a few permanent retaining walls already being built. At least, I assume that they're permanent - in the photos, they look like stacked stone, which seems temporary, but then again, it's stacked finished limestone, which I assume isn't cheap even in Texas. I know we pay a lot here for Texas limestone, but maybe it's cheap enough there to use as riprap?

That wall lies between the track areas of Turn 2 and Turns 17-18 and retains the earth there, not the track. ETA: BTW, the wall is very thick concrete & stone, but I can see how it looks like stacked stone in distant photos.

Yeah, that's the wall that I'm thinking of. In other areas, they've poured concrete walls like you'd expect, but here they've opted for stone. (Actually, you can see one of the concrete walls in the photo.) There's a close up photo of the stone wall that I can't find where it seems clear that it's a dry-stacked wall. I just thought it was odd, especially given the soil conditions. Maybe there's a soils guy here who can enlighten us.

[hairy_scotsman]

There's a close up photo of the stone wall that I can't find where it seems clear that it's a dry-stacked wall.

I added a photo above that's probably the one you're referring to. If you look closely between the stones you can see the wet mortar. It also looks like there may be a vertical layer of pure concrete behind that as well. Hard to tell.

[Pup]

Yep, you're right. Very deeply raked mortar joints, though. And not the very best work I've seen, to be honest. I'm used to seeing it like this...


Mondrian Wall by PhotoGrandma, on Flickr

Maybe they're going to go back and tuck point it all, but jeez, that's a lot of work.

[hairy_scotsman]

Yep, you're right. Very deeply raked mortar joints, though. And not the very best work I've seen, to be honest. I'm used to seeing it like this...

Yep...me too. Maybe that's the "rough draft" and will be filled in later? No construction or masonry expert here.

[Scorpaguy]

re the rough joints...maybe they are going for that typical "American Southwest" look. A bit rustic...and not necessarily any less structural integrity. Pup's pic looks typical British or New England. I hope we have some "Alamo-ish" looks...maybe even some Native American motiffs in the landscaping.

[IchII3D]

In some ways I think the US could make a great track, they are very focus on making something that would be great for spectators, much like NASCAR and this could essentially create a great viewing experience but most of all, great elevation. Slowly but surely I hope it changes the American view on circuit racing, I believe NASCAR would be an amazing sport if they dumped the ring and turned it into something like the Australian V8 series.

But anyway, I'm super excited about any new track as the cars are gradually evolving out of the old and into the new. Although obviously I would never remove the old classics.

[Ray]

Yep, you're right. Very deeply raked mortar joints, though. And not the very best work I've seen, to be honest. I'm used to seeing it like this...


Mondrian Wall by PhotoGrandma, on Flickr

Maybe they're going to go back and tuck point it all, but jeez, that's a lot of work.

To me, that wall is extremely ugly. It could easily be just concrete with a pattern pressed into it to make it look like stone block. The old apartments I lived at did the same thing for the bricks on the property entrance. They laid down red concrete mix and pressed a brick pattern down onto it and threw stone dust on it before it dried. To me that's lazy, cheap and insulting to me considering what I paid to live there. For what they charged me to live there, they should have laid real brick instead of what they did. You see that in new home construction now all over the US. They cut corners to save a buck and that kind of cheap and lazy construction makes houses ugly and fake looking. Both of my neighbors houses have that kind of crap all throughout their houses and it's such a waste of time and material to fake something that isn't that much harder to do the right way.

I'd rather have the one in the other pictures at the track. It looks like someone took care and personal pride in making that wall and fitting all the stones in there right. Sure it's aesthetic, but I like something that looks handmade rather than smoothed out a lifeless. I sincerely hope they don't go back and fill those spaces in flush. It would lose it's appeal to me and look cheap and lazily constructed. For what this place is going to end up costing, they'd do themselves and the patrons a service by doing real hand construction rather than neutering it and being cheap. Having deep mortar lines and not perfectly smooth doesn't mean it's shoddy construction, it's just a different style. If it weren't going to hold together, they wouldn't have built it that way. They are already pressed for time so I seriously doubt they are going to go back and spend more time re-doing an already finished project.

[Pup]

Having deep mortar lines and not perfectly smooth doesn't mean it's shoddy construction, it's just a different style.

You can have a well built rustic stone wall, or a shoddily built rustic stone wall. I didn't post the photo to say that refined is better than rustic, but to merely show what I'm used to seeing. Texas limestone has subtle color variations that are lost in a rougher surface. So since it's expensive here, people only buy it if they specifically want a very neutral, even surface, and so it's usually only used like I showed it. There are other stones, with more color variation, available here that look better with rustic styles. Of course, in Texas, the stone will not only be cheaper but they'll have a tradition of using it in ways that would seem out of place elsewhere. But, to be clear, while I applaud them using local materials and a regional vernacular, I don't see a lot of craftsmanship in what they've done - rustic doesn't infer well-crafted - but then they aren't finished so we'll see.

[strad]

So now we are going to hassle over the aesthetics ???
Do the armchair quarterbacks get to criticize color choices as well?

[Mr Alcatraz]

That's my assumption, but then there are quite a few permanent retaining walls already being built. At least, I assume that they're permanent - in the photos, they look like stacked stone, which seems temporary, but then again, it's stacked finished limestone, which I assume isn't cheap even in Texas. I know we pay a lot here for Texas limestone, but maybe it's cheap enough there to use as riprap?

The part I emboldened is something I think we need to determine. If it is a permanent retaining wall, depending on its load, it has to have a concrete footing and proper rebar placement. I'm not sure about Texas but that looks to me that it might require a "keyed" footing depending on the height. Some of that wall looks like it is over 5.5ft high That would require a keyed footing(in California). I've attached a pdf, it is only 4 pages and the diagrams on the last 2 pages have good examples of keyed footings. Its purpose is to keep the wall and footing from moving/sliding if the bottom of the footing is flat.
Hairy were you there when they started building the wall? Maybe you can shed some light in this matter?
http://www.sdcounty.ca.gov/dplu/docs/DPLU084.pdf

he'd be absolutely aghast at that stack of s***. Uneven, not cut properly, not filled in properly

Your father may have also known that "Only children and fools are judges of half finished work".

There is also this:
http://www.theaustingrandprix.com/news/ ... ricas.html
I'm not sure who is doing the analysis but it refers to retaining walls 8 to 15 ft tall.


Example of retaining wall; source: Building Construction Illustrated//Retaining Walls

From photos released as early as October 26th, we can see evidence of retaining wall construction around the track. With a high degree of elevation variability, the track design calls for a substantial amount of retaining walls to assist in the retention of earth and allow for drastic shifts in elevation. Keep in mind that soil can only be modified to 1:4 rate (1 foot rise per 4 feet length) and anything beyond this requires a retaining wall to hold it back.

In these photos from COTA, we can see retaining walls from approximately 8ft to 15ft tall, all constructed with site-cast concrete. Site-casting is the term for concrete structures are constructed on site with wooden or metal forms to shape the concrete. From the illustration of an example retaining wall, we can see that there are two pieces, the footing at the bottom, and a wall which sits on top. The footings are poured first, and then the wall is poured, both with lots of steel reinforcement to increase strength. From the photos of the retaining walls, we can see evidence of these different components as workers construct form-work and tie steel reinforcement to prepare for the addition of concrete.

While not the most glamorous of features at COTA, retaining walls are an essential part of the design of the facility. They provide a tool for designers to add elevation shifts and minimize the cost of reshaping the land, and therefore an integral part of the 133ft of elevation change at Circuit of The Americas.