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Everything posted by Purdueenginerd

  1. The use of dimensional timber for the stud framing and then use of light gauge for the floor framing is a little unusual to me. Nothing structurally wrong with it, but I'm curious the rationale behind it. Have not run across that before.
  2. Building being demolished this morning. That building used to have an old sign with a 1950's era car. Hope someone saved that sign.
  3. The TC Jester/19th street commercial big box stores need to be revised. Hopefully developments like this encourage growth in that area as well.
  4. I've got a project right now where the owner wants to add a swimming pool the roof an existing two story building. The roof framing is bar joists. Long story short, we performed a feasibility study to see what would have to be done. I think they laughed out loud when I told them the roof framing failed by a factor of 10, the columns failed, and even the foundations failed. They still want us to design new framing to support the swimming pool. Luckily this garage is new construction, but it does kind of concern me that theyre goign to put a swimming pool, full of chlorides over the top of the garage with all its exposed elements... This is going to be a maintenance issue for the owner
  5. Saw cladding going in yesterday on my drive home. Very little thus far.
  6. To add, There are economic benefits to mass transit systems as well. Given the opportunity high rise developments can reduce the costs of construction for onsite parking. Parking garages and structures are low profitability land that right now current infrastructure requires. If you give people more options on how to get to work, you give developers the opportunity to use land for more profitable uses. More shops, more offices, more residential in the same square footage that would have been occupied by parking before. Right now, for large swaths of Houston, the automobile is the only means of accessing our city.
  7. Did a quick peak. Used to be houses on the lot in the 1940s and 50's, then it was mostly warehouses up until about 2016. Been clear for a few years now. Good infill project. Kind of boring appearance wise, but it works for the area in my opinion.
  8. I didnt even think about that. Oh how I loath open floor cube concepts.
  9. Ive been noticing this lately (in single family homes), and maybe the architects can chime in on it. But I've noticed more and more structures with painted black elements on the facade, and I was wondering if that has any deleterious effects on the energy efficiency of the building.
  10. Its a gas station, someone on Nextdoor pulled what looked like a permit. Gas station for sure.
  11. Oil just hit 5 dollars a barrel: Thats still going to be apocalyptic for the Texas Economy, even with the reduction of oil dependency over the last 40 years. Part of this is demand driven, so presumably if COVID 19 starts to free up sectors of the economy by summer, demand might go back up some. But 5 dollars for a barrel is just not going to sustain many businesses at current production levels.
  12. The set back is fine, in my opinion, but as Texasota stated, as long have something there. If they have a wide sidewalk an planted trees - Great! but if its a 3' sidewalk (or no sidewalk), separated from the building by 15 feet of grass than, I'll be disappointed
  13. We've now had a couple of larger jobs in design phase in Houston and Austin put on temporary hold by ownership. This will trickle own to construction eventually.
  14. @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.
  15. Dont believe this is applicable to this forum. I have fond memories of ashville though, good hiking.
  16. I have a tiny repair project at a hotel. They are Howling about price for the repairs and trying to equivocate whether the repairs are needed. I imagine this is related.
  17. My specialty isnt bridges, but it is important to note that the code that governs the structural engineering of bridges (AASHTO) is generally more stringent than the code(s) that cover buildings. The statement in the news article is alarming but sort of vague. A brief explainer on load combinations. In both the building code and bridge codes, the predominant system of design today is Load Resistant factored design. (In Wood, Masonry, Soils and some steel structures - the old system is still used sometimes,). Long Story short, the engineers classify different types of loads. I'll just use 3 for example, but there are a lot more. Dead Load(DL) - Self weight of the building/structure Live Load(LL)- typically a transient load/mobile load ie, people. Wind load(W)- Pretty self explanatory. The engineer takes those loads and applies factors to them. Then puts them in different combinations! For example, in the building code here are 4 combinations that you'll likely see. 1.4 * D = Factored Load 1 1.2 *D +1.6L = Factored load 2 1.2*D+1.0W+0.5L =factored load 3 0.9*D+1.0W = factored load 4 Then for each member in a building, the engineer will compare all the load combinations with the capacity. I'm only showing you 4 load combinations, but the structures I work on, its not unrealistic to have 20 to 30. Accounting for wind directions, uplift etc. This system results in "more efficiently" designed structures. A brief example fictitious example: I have two buildings that weigh 2000 lbs: 1 building has to hold up a 1000 lb statue. The 2nd building has to hold up a dance floor with for 1000 lbs of people. Building 1, per code, would have to be designed for 1.4*(3000lbs) = 4200lbs Building 2, per code, would have to be designed for 1.2*2000lbs +1.6(1000lbs) =4000 lbs The reason i'm goign through this giant explanation is that the bridge code, has even more load combinations. Including load combinations on specific lanes loaded, and other lanes unloaded. They got load combos that include vehicle braking force, thermal force, wind, seismic, ice, rain, snow, the list goes on. What this sounds like to me: They missed a load combo. Does it mean it will fail? Not necessarily. It sounds like theres a potential for damage during a load imbalance. Which may get remedied by restricting the amount of lanes in the south bound span until the other span is complete. This is the more concerning to me. The soils part is a bit alarming, because I would presume a pretty substantial geotechnical report was performed for this test. I would imagine they have cut into a bit of their factor of safety for one of the load combinations. Without knowing what exactly is wrong regarding the stability, I cant imagine a full demolition and start over is cheaper than trying to make modifications to the existing structure. I could see it being done out of an abundance of caution, mostly because things went south very badly with the FIU bridge. Anyway, apologies for the wall of text.
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