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Showing content with the highest reputation on 03/31/20 in all areas

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    That is awesome! They are bridge riggers, whatever that is. https://www.google.com/search?q=bridge+riggers&source=lmns&bih=1307&biw=2560&safe=active&hl=en&ved=2ahUKEwi88MnBhsXoAhVtg60KHbANBa8Q_AUoAHoECAEQAA
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    This is the Baby Yoda of cranes.
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    @hindesky Those are post tension or prestress ports. There are three times of structural concrete construction 1. Traditional Reinforced concrete 2. Post Tension Concrete 3. Pre-stress concrete To understand the three, a brief cursory explainer on how structural concrete works. Concrete is very weak in tension, Great in compression! Lets talk about No. 1 first. In traditional concrete, lets imagine a simple concrete beam with no reinforcement (ie, rebar). Concrete, like every material on this planet, will bend. If you imagine a sagging beam, the bottom of the beam will be in tension, and the top of the beam will be in compression. With no rebar, the concrete will crack at the bottom and quick propagate upwards, splitting the beam in half and causing collapse. Ever see a martial artist break concrete block in half? This is exactly what is going on. Theyre impact is "flexing" the block, creating tension on the bottom face and subsequently breaking the block. In traditional reinforced concrete, rebar is added to the bottom of the beam to engage and resist those tensile forces. Above is the cross section of a typical reinforced concrete beam design. I wont go into the equations too much, but you'll see that the top of the beam is in compression, the bottom of the beam is in tension (as denoted by C and T, respectively). Now what are the limitations for this? In traditional concrete construction, the tension zone effectively always exists, this limits how long the span is. In addition the more load you have on it, the "deeper" the beam required to create a sufficiently large concrete compression zone. For parking garages, is generally desirable to have long spans between columns because that means: more parking! So what is post tension? When the concrete is cast, they create this holes all the way through the beam/girder all the way to the other end. While the structure is shored, they'll run these high strength cables through the beam and tie them at both ends. The cables are then tightened, aka, tensioned, and locked in place. The tension in the cables in effect "compresses" the concrete. Remember concrete is great in compression. Post tension effectively put more of the concrete section into compression. Advantages include the ability to go longer spans with less depth. Disadvantages: less modifiable and more expensive to build-- Can also be dangerous if a cable fails. To answer your question, those holes are for post tension cables. Pre-stress is very similar in principle. You will most often see pre-stress concete in pre-cast garages. Prestress means that the cable was tensioned before the concrete was cast, then they poured the concrete and subsequently released the cables from tension, (which then applied a compression force on to the concrete. These are common at plant manufactured concrete shapes, that are trucked to the job site and put in place at the construction site. The disadvantages are similar to post tension. As for why theyre working on an already existing garage: Not sure. unless it was to make repairs or modifications. associated with the builing that may go up next door. This garage looks like a pre-stress/precast garage.
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    I remain hopeful that the world will return back to normalcy, eventually. Seeing commercials about "no contact" is so unnerving. I get businesses will capitalize on this I just didn't expect it so quickly. Gas going under a $1 per gallon is something I would have never thought I'd see again.
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    And that's the part of this i don't understand. If they were talking about ripping up 527, I'd be opposed to that. But here we have two ramps right next to each other. Surely we don't need two ramps in such close proximity.
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    No, Momentum Audi property. The VW place is at 2405 Richmond, this is 2315.
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    I didn't know bots could get drunk!
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    I took a couple pictures but my disk is full and won't download to my computer. I talked with the guys who were repairing the tension cables on the parking garage. I asked them if they knew about the apartments to be built but they didn't have a clue. To me it appeared they were tensioning the cables and then putting new cement over the ends.
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    Will be really interesting to see if this one still goes through.... fingers crossed.
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    I walked by Block 98 this morning. Not sure what was going on, but there was certainly activity with a few workers on-site. Maybe we begin seeing more progress in the coming weeks and this is still on schedule for 4/20 start date?
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    Nahh, they will convert it to a luffing crane, and keep extending the jib, then leave the crane buried in the building when they are done.😁 (cabin fever is making me loopy). One of the coolest things I ever saw with cranes was in Doha, where they disassembled the crane tower from the bottom, and dragged the sections out of the basement before closing up the access hole. That was for a luffing crane in the middle of the structure. I had wondered for a year if they were just going to leave the crane tower in the building, but that seemed an expensive waste. On another building, there was the luffing crane on the edge of the building where I saw some guy with a pile of rags walking on top of the operator cabin, not tied off, carefully cleaning everything. Pretty scary to watch since the cabin was 200+ feet off the ground.
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    Much bigger crane this weekend. It was about to hoist up a Madea Mini Crane. https://www.maedausa.com
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    its a very clean and sterile design...and it has the same shape as the anadarko tower...
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    yeah it reminds me of pinehurst, NC or peachtree city, GA both masterplanned towns it makes for a very natural and very appealing setting
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